#036 - Chief: Indian Boomerang Puzzle

#035 - Checkers: King Me! (Forever)

Realised thumbnails might help the videos... bear with me as I figure out a style I like.

Release Date: July 1973

Platform: Mainframe (BASIC Type-In)

Genre: Board Game

Developer(s): Alan J. Segal

Publisher(s): Digital Equipment Corporation

It's been a while since since I talked about the board game Checkers... or Draughts, if you prefer. In fact, it was one of the first games I ever wrote about - what I consider to be the first true video game ever created - back when computers were the size of houses and programming then was akin to the dark arts.

Twenty years on from then, it's a different story. Massive improvements in technology, computers decreasing in size and price and - most importantly, an easier way to code. Being able to make such a comparison makes it a great time to revisit the theme of the first video game.

Seeing as I didn't do so in that first article, I'll start with a brief introduction of the board game Checkers, a.k.a. Draughts.

A Brief History of Checkers

According to online sources, it's entirely possible that Checkers has a history dating back to 3000 B.C. However, just to temper the potential excitement that comes from a date like that, it's highly speculative. In reality, the best conclusions arrived to with some degree of certainty on Checkers' origins is that it's likely derived from an ancient game called Alquerque. That's also where you end up if you forget to take the left turn at Albuquerque.

May look familiar to some.

Alquerque dates back to the early-mid 2nd millennium B.C. (~1400 - 1000 B.C.) Sources seem mixed on this, but that's the general dating given. It was played across Egypt and the Middle East, being brought over to Europe through the Moors in Spain during their invasions in the early 8th century A.D.

From Alquerque, we fast forward a few hundred years and move north into France, and Checkers finally takes the form we all know today. Somebody in France in the 12th century got the idea to play Alquerque on a Chess board, and that's it - Checkers was born. Nobody seems to know who the individual was that did this, but I hope they got knighted, or whatever the 12th century French equivalent to that is. 

The rules for this new "hybrid" game - if I dare use such a term - were developed steadily over the centuries, with many regional variants also developing across Europe that deviate from the standard Checkers rules: a larger or smaller board, and non-diagonal movement are some of the distinctives to other variants.

Computer Checkers

Moving forward to the age of computers now. We've already seen the first attempt at making a Checkers computer game as arguably the first video game ever created, back in 1952 by Christopher Strachey (check the link at the start of the article for more about that one). Now, 21 years after Strachey's game, we have our second (or possibly third - there's another 1952 Checkers game out there that I might need to investigate...) go at making a Checkers computer game, written in BASIC, this time.

The lady looks utterly thrilled...

This Checkers game is yet another of the many games from David Ahl's 101 BASIC Computer Games book. Although, he isn't the author this time. Alan J. Segal is the credited author, of whom we regrettably, once again, know nothing about. Don't even know if he was a high school student, university student, professor - diddly squat.

We haven't had one of these in a while, but this is also one of those annoying instances where the game was significantly modified between the original edition of 101 BASIC Games and the 1978 microcomputer revision. I determined that I'd be happy to still play it here in the 1973 coverage as it's still the same game at heart. Steve North and Lawrence Neal of Creative Computing (Ahl's post-DEC company) just modified some (note: some) bugs out of the game, like fixing being able to double or triple jump without threat of losing your own piece instead. They also programmed in a way for the game to know who's won. I would've thought that that would be... important for a video game, y'know?

The opening screen is also too big to fit in one photo.

Oh, but there's even more to say about the game, after I started playing it. The typical Checkers ruleset only allows pieces to move diagonally forward. Diagonal movement is still the case in this game, but it doesn't prevent backwards movement. So you can basically cheat to win, as the computer will never move a non-kinged piece backwards. I did this in my first playthrough, as I couldn't remember whether Checkers rules allowed for it or not. Keep in mind, I like to do my first playthroughs before I do any research. I didn't win my first attempt - it got into an unwinnable position, so I reset, and won my second attempt, using backwards movement. Once I started looking into how Checkers is supposed to be played, only then did I know for sure that backwards movement wasn't in the standard ruleset. There's also a rule that requires you to jump a piece if there is an opportunity to do so on your turn. This is also not enforced in the game, either. Once I began my research in official Checkers rules and strategies, I imposed on myself the standard ruleset in the interest of honouring how Checkers is meant to be played.

But, don't just think that only you, the player, can cheat. The computer can also cheat, but in a far nastier manner. While North and Neal fixed some of the bugs in Segal's original code, they didn't fix everything. There happens to be one very nasty glitch that they didn't fix, which allows the computer to spawn effectively an infinite number of king pieces. I'm dubbing this the "Infinite King Glitch." Only the computer can effect this glitch, where the game, instead of moving the computer's piece to the back row to be kinged, instead spawns a new, kinged piece on the board, with the piece that was supposed to be kinged not moving at all. I had a game occur where the computer spawned six kings with this glitch.

"Infinite King" glitch in full flight. Continuously being spawned by the X on 1,1

One small mercy is that the computer is quite the incompetent Checkers player. It starts every game with the worst possible starting move - I believe it's 24-20 in official terminology; 1,5 -> 0,4 in the game's terms - allowing you to counter with the best possible starting move (called 11-15; it's 2,2 -> 3,3 in this game), giving you an immediate advantage. Once I learnt how to play the game properly, this made beating the computer all the more easy.

Even computers fall victim to the Checkers noob trap.

What was less easy was wrapping my head around the control scheme of the game. Unlike official Checkers terminology, Segal's game does not number each of the playable squares on the board from 1 - 32. Instead, it uses the cartesian co-ordinate system - though a confusing implementation of it. One might expect the bottom left point of the grid here to be 1,1, but it's actually 0,0 here. This put me in a spin regularly throughout my first few rounds until I got the hang of it - constantly having to do mental math in my head, making sure I was inputting the correct co-ordinates I was moving a piece to. To make matters even worse, I couldn't figure out at first how to stop a piece after jumping, and ended up crashing the game. The game can't detect whether a jump is a single, double, or triple, and it expects you to input negative co-ordinates to cancel the jump. Because I'm daft sometimes, I didn't see that the in-game instructions tell the player this.

The issues don't end there, though. The more I played, the more technical issues I ran into with Checkers. One game, I was doing quite well, giving the computer a good thrashing, when the game suddenly decided it didn't want to be played anymore. The below picture tells the story:

I guess the computer got grumpy from losing.

There I was, making another jump, capturing another computer piece, when the "!NEGATIVE ARRAY DIM" line shows up. The game had crashed. Just as I was about to win, too! How rude. I don't know what the terminology means - I'm no programmer - so if anyone does know what this BASIC error means, please let me know in the comments.

Despite all this, you may be able to tell that I played quite a lot of this Checkers game. I think I maybe played for a couple of hours all up. It turns out, I actually quite like Checkers as a board game. It's one of those funny games, where you play it as a kid and don't think much of it. Growing up, one might see it as a simple game that doesn't have much to offer. I know I did. It turns out I was wrong on that point. While it doesn't quite match the strategic depth of a game like Chess, Checkers offers a surprising amount of depth in its strategy and ways of playing. The research I did on Checkers strategy, which can be found here, if you'd like to understand more about the game yourself, opened my eyes up to what Checkers truly has to offer as a game of strategy.

I'd consider that a downright thrashing.

As a result, despite how truly broken Segal's Checkers game is, I found myself strangely addicted to it. The broken-ness was more a point of laughter and derision than it was a source of frustration, because I couldn't help but chuckle at the absurdities present within the game.

All that in mind, the scores ended up being quite lopsided for this game:

Time Played: 2 hours

Difficulty: 4 (Mild)

Between the computer being a bit of a dim Checkers player, and the ability to cheat, it's not terribly difficult to win, but does at least require some thought and awareness of what's going on. The computer can still jump you if not paying attention.

Gameplay: 4

Whilst I discovered that I really enjoy Checkers as a board game, this computer game version leaves a lot to be desired. Technically, it's a mess, and doesn't enforce basic rules, allowing the player to effectively cheat. And again, the computer is not very good at the game. One later port of the game compares the computer's competency to a six-year old playing for the first time. In short, source game = good, implementation = terrible.

Controls: 3

I found the game's control scheme somewhat unintuitive, and quite cumbersome. The grid starting at 0,0 I found terminally confusing, and I constantly made co-ordinate errors, even after playing it for a couple of hours.

Visual: 2

The visualisation of the Checkers board is appreciated. The squares are spread out not too close, nor too far apart to make the board easy to read.

Functionality: 2

I think this the worst game I've reviewed so far from a technical basis. And this version has even less bugs than the original. From the Infinite King glitch, to the game not acknowledging the basic Checkers rules, to just crashing randomly - this game is quite broken. Playable, but broken.

Accessibility: 2

All of the above makes the game hard to recommend. Unintuitive controls, glitches, you name it. It's not completely impenetrable, as I think most people know the basic gist of Checkers, so the game saves itself from a worse score there.

Fun Factor: 6

It's bizarre, how oddly fun this game is. It's utterly broken, poorly programmed, yet somehow attractive and slightly addicting. It may have helped if the computer was a more formidable opponent, but for a novice such as myself, it proved enough of an acceptable challenge to make me want to come back to try and beat the computer again - with the added challenge of preventing it from triggering the Infinite King glitch.

The amusement that Checkers gave me unfortunately isn't enough to truly redeem it in any sort of fashion. It only gets a score of 19, which puts it with the rest of the 19s at the bottom of E tier. Of course, Checkers sits at the top of that pile because I actually had fun playing it, unlike the rest of that sorry lot. Still, it's a terrible, incompetently-put-together attempt at computer Checkers that I don't recommend you try.

#034 - Bullseye: Never Tell Me the Odds

Release Date: July 1973

Platform: Mainframe (BASIC Type-In)

Genre: Sports

Developer(s): David H. Ahl

Publisher(s): Digital Equipment Corporation

We are staying in the sports arena this week. This time it's a slightly less-flashy and far less dangerous sport compared to bullfighting. Darts is... an odd sport to me, to say the least, but one that has a cult following (as far as I can tell,) particularly in the United Kingdom. While odd, I have come to appreciate it, through my research for this article, as a neat sport that combines a physical skill (throwing) with a mental skill (speed arithmetic) that also doesn't require you to have a perfectly sculpted athlete's body to be good at. My beanpole figure certainly appreciates that - it's the throwing that worries me.

This digital interpretation of the sport, written by David Ahl for 101 BASIC Computer Games, runs just a little bit differently to the Darts I think most readers would be familiar with. It's a heavily simplified take on the sport that omits several rules and mechanics seen in the real thing.

The original Bullseye page. I'm waiting for Porky Pig to pop out of the centre of that image.

It's like this: the dart board in Ahl's Bullseye (oddly similar name to Bull) only has zones of 10, 20, 30 and 40 points - and you can also miss for 0 points. The aim is to get to 200 points first, which is relevant for the multiplayer side of the game, which I'll get to in a moment. 

In professional Darts, the score counts down from 501 or 301, and has all the numbered sections from 1 - 20, double and treble (triple) sections, and the two-sectioned bullseye of 25 and 50 point zones. The winning throw in the standard 501/301 rules also must be a double. All of that is omitted in Bullseye. That being said, I still think that the spirit of the original game is somewhat present in Ahl's Bullseye, and isn't completely unrecogniseable.

Now, the multiplayer. It's very clear to me that Bullseye is designed around its multiplayer component. This game's taking some inspiration from PLATO, it seems, as Bullseye is a big multiplayer game. How many players can throw per game? 

20. Twenty. 

For an early 1970s text-based BASIC game, that's completely unheard of. The only other game I can think of that allows more than 2 players to compete is Horserace, which allows a measly 10 players to bet per race, in comparison to Bullseye's 20 shooters lining up to throw. I don't know if anyone ever tried this with 20 people, I can only imagine it taking a long time to get through everyone, especially with how slow the old mainframes were compared to modern computers.

1978 edition. That kind of dart would definitely be illegal.

While Bullseye takes a simplified approach to the scoring, how it manages how you throw the darts is a little more interesting. At the most basic level, it reminds me a lot of Dartmouth Championship Football or PDP-10 Timesharing Basketball's design. There are three different throws you can choose from: 

1. Fast overarm.
2. Controlled overarm.
3. Underarm. (I have never seen anyone throw underarm before. Is this really a thing?)

And the results of your choices are... not random! Yes! Unlike those other two games, each throw has been coded with specific odds, so there's a real choice this time. In the most basic terms,

1. Fast overarm has the highest odds of a bullseye, but also a 50% chance to miss.
2. Controlled overarm is the most reliable and least likely to miss, but also least likely to get a bullseye.
3. Underarm is slightly less consistent than Controlled Overarm - more likely to miss, but also more likely to score a bullseye.

However, I discovered, while preparing for the video, that there's in a fact a coding error present in Bullseye. Whilst the odds above are the intended design, there's a mistake that causes Fast Overarm and Underarm to have the same odds. I thought at first that this was a copyist's error, that whoever copied the code down for Vintage BASIC made a mistake, but no - it's actually printed in the book! Look at the above picture of the 1978 edition page. Line 190 is the offending line - it goes,

190 ON T GOTO 200, 210, 200

I've italicised the mistake. That second 200 is meant to be 220. That's the part of the code that tells the game you've selected throw 3, and to run the odds in the lines below. Selecting throw 3 incorrectly tells the game to go to throw 1's odds on line 200, instead of throw 3's on line 220. Oops. The good news is that this is a very easy fix, even if you don't know programming. You can open the file up in Notepad, and just change that incorrect 200 to 220, and everything will run as intended. Coding lessons with OGC!

[Disclaimer: I don't know how to code BASIC. I take no responsibility for errors made during my lessons.]

Bullseye's intro screen. Don't believe everything you read.

Anyway, now that that's dealt with, back to the game. Each throw presents a different level of risk & reward (with the code fixed,) which is especially great for multiplayer, as you could adjust your throwing strategy depending on how other players' throws went. Go big if you want to try and get ahead, or play it safe if you don't need a bullseye to win. 

Controlled Overarm will get you points - but not the big points.

In solo play though, it doesn't really matter that much. I'll provide the full odds table at the end of the article - to avoid spoilers - but I will say that there's no point in going for any throw other than the Fast Overarm. That's simply because it has the highest odds of a bullseye, at 35%. Yes, the in-game description does lie to you about that one - it's not perfectly 50-50, which I assume, based on the way the odds are designed, is for balance (see the table at the end.)

Go big or go home - way more fun.

If you want to get a "perfect" game - the equivalent of a real-life "9 dart finish," which in Bullseye is instead a "5 dart finish," (5 x 40 = 200) your odds are around 1.5% with the Fast Overarm. I've seen much worse odds in other games, so that doesn't bother me too much. Shiny Pokémon, anyone?

You'll see in the video at the top that I had a few goes at hitting the 2% 5 dart finish. How did I do? Well, watch and find out! I'm also trying something new with the videos in commentating them and doing some extra editing. I expect that not everyone who reads the blog watches the channel, and vice versa, so it might be good for the YouTube-only side to get some extra information on the games, provided they can tolerate my voice. Anyway, let me know what you think on that change.

The odds for the 5 dart finish are very low, but what about Bullseye's chances of getting a good score? Let's find out now.

Time Played: 25 minutes

Rounds are very short in solo play - 20-30 seconds - but I did play it quite a bit trying for a 5 dart finish.

Difficulty: 1 (Brain-dead)

There's really nothing to it from a skill perspective.

Gameplay: 4

I very much appreciate that the throws are distinct rom one another, leaving opportunity for strategic choice - mostly in multiplayer. However, I don't think there's enough difference in odds between Controlled Overarm and Underarm (see table below) for there to be much of a strategic choice between the two. Underarm is just better. Unfortunately, it all falls apart in solo play, as there's really no choice at all once you know the odds. Nor is there much point to even playing it.

Controls: 5

Very standard for a text-based BASIC game.

Visual: 2

Bullseye gets a bonus point for having some very neat and tidy text formatting.

Functionality: 4

There is an error in the source code that ties throw 3's odds to throw 1's. It's an easy fix that I picked up on only after I did these scores initially and was preparing for the video. Line 190 is the offending piece of code, for anyone wondering. It's a pretty easy fix, even if you don't know BASIC programming.

Accessibility: 3

I think it's fairly standard for a text-based game. One could maybe make an argument for it being a little more accessible, seeing as it more a numeric-based game, rather than a reading-based game.

Fun Factor: 4

I'm really just scoring it up for the multiplayer potential. I genuinely think this would be a decent time with a group of friends. Personally, I think I had more fun dissecting the throw odds than actually playing the game.

Bullseye's dart throw lands it a score of 22 and into the E tier. It was tied with Dartmouth Championship Football - before I found the coding bug. Now it sits just below it, right next to Bull, funnily enough. That's the cost of having bugs in the game - throwing away free points in my metric. This also marks the 50th game registered in the Tier List.

And finally, as promised, here's the full odds table. If you're wondering how I got this - the 101 BASIC Games pages provide the calculations, with Underarm as the example throw. Just look at the source code on the page over, switch the numbers and - presto! - you have the odds for all three throws. "SPT" indicates the average "Score Per Throw" of each throw type:

Different, but also not different.

My "balance" remark earlier was a little hint to the reality that each throw comes out, on average, exactly the same. You might think this results in an "illusion of choice" scenario, but it in fact does not. If you tested each throw 100 times, you'd come out with a result that looks like the table, but in real play, it doesn't work like that. The way I see it, there's not much point ever going Controlled Underarm unless you really want to make sure you get that winning throw and don't miss. But there is rationale for choosing either Fast Overarm or Underarm, depending on your proclivity for risk-taking. This all only applies to multiplayer, by the way. I'm still only ever going Fast Overarm on my own for that 5 dart finish.

There was surprisingly a lot to talk about with this game. I don't mind it