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Greenblatt (Computer)
Number of games in database: 8
Years covered: 1967 to 1977
Overall record: +1 -6 =1 (18.8%)*
   * Overall winning percentage = (wins+draws/2) / total games.

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(born 1966) United States of America

[what is this?]

Also known as MacHack (it was one of the first ever computers to be allowed to participate in a tournament: those like Toronto's Labour Day classic), its programmer was Richard D. Greenblatt. It superceded some of the routines developed by Mr. Kotok, Paul W. Abrahams and John McCarthy at MIT under Project MAC for machines such as the PDP-6, later ported to the PDP-10. Mr. Greenblatt, Donald E. Eastlake III & Stephen D. Crocker later released its source code as it acheived a USCF rating of 1243 in 1966. Larry Kaufman helped write part of its opening book. It was the first program to play in a tournament against humans and achieve a chess rating. It is an honourary member of the Massachussets State Chess Association.

Last updated: 2018-12-04 03:34:44

 page 1 of 1; 8 games  PGN Download 
Game  ResultMoves YearEvent/LocaleOpening
1. C E Wagner vs Greenblatt 1-0551967Winter Amateur TournamentA00 Uncommon Opening
2. NN vs Greenblatt ½-½331967Tournament 1C58 Two Knights
3. Greenblatt vs B Landey 1-0211967Massachusetts State ChampionshipB20 Sicilian
4. P Haley vs Greenblatt 1-0471969Labour Day OpenA04 Reti Opening
5. Greenblatt vs J A Curdo 0-1351971Greater Boston OpenC82 Ruy Lopez, Open
6. Fischer vs Greenblatt 1-0211977Computer MatchC33 King's Gambit Accepted
7. Greenblatt vs Fischer 0-1391977Computer MatchB92 Sicilian, Najdorf, Opocensky Variation
8. Greenblatt vs Fischer 0-1471977Computer MatchB27 Sicilian
  REFINE SEARCH:   White wins (1-0) | Black wins (0-1) | Draws (1/2-1/2) | Greenblatt wins | Greenblatt loses  

Kibitzer's Corner
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Jun-07-11  Graham1973: I may have hit similar problems with trying to convert the notation of an old newspaper account into algebraic notation. As far as I can tell everything is correct but I get errors when I attempt the conversion using CHSBD.
Jun-07-11  Petrosianic: This is the real problem with Descriptive. It's more of an art form than algebraic. The art of saying exactly what you need to say, but no more. Like B-QB4 is "wrong" if B-KB4 is legal. "How can that be wrong?", one might ask. The Bishop moves to QB4. Yes, but that's more than you need to say. You only have to say B-B4 in that case, so B-QB4 is unnecessarily verbose.

The problem is that that would lead to notation errors when both moves were technically possible, but one was so poor that nobody would consider making it. Like if B-QB4 and B-KB4 are both legal, but black has a pawn on e5, and so B-KB4 would just hang the Bishop, a player might tune the move so completely out of their consciousness that they wouldn't remember that it was legal when it came time to write the move down. I found a lot of notation errors like that in my early games when I tried to enter them into the computer.

Jun-07-11  Tomlinsky: All of the moves transcribed are legal and the errors, and moves themselves, make sense assuming it was a time scramble at the end with a low rated player with a computer looking, maybe, 2 or so 1 or 2 Ply when moving quickly. This is 1967. I'l wager the score here is correct.
Jun-07-11  Tomlinsky: As Petrosianic notes, descriptive could get very messy. Ambiguities and erros were easily made in time trouble. Move 26 had to be a bishop move and ignoring the rook check that was impossible the move itself was legal as were the following moves. It does match up with the game in the notes... in the end.
Jun-08-11  Graham1973: You might want to mosey over to the Daniel F M Starbuck to have a look at a game I'm trying to convert to algebraic but am having problems with. I'm simply not an experienced enough chessplayer to work out what is wrong with the moves.
Jun-08-11  Petrosianic: Oddly enough, in looking over those early games, I found that although I'd made plenty of errors of ambiguity, that I'd made very few errors involving square naming (like saying R-Q2 when it should have been R-Q7). This is the kind of error people seem to expect from Descriptive, since after all, every square has 2 names. But it was much less of a problem for me than the B-B4/B-QB4 type of error. It was actually more natural than algebraic in that respect, since no matter what side of the board you're sitting on, the numbers increase as they move away from you, which is easy to remember.

Another advantage of algebraic that almost nobody talks about: It's much easier to type. If you want to type the move B-QB4, you hit and release the shift key twice. But to type Bc4, you only hit and release it once (and you also only type 3 characters, rather than 5).

Jun-09-11  Tomlinsky: <Petrosianic> I wouldn't use descriptive these days but something I've occasionally pondered on, that is also pertinent to language in general, is that language itself influences the way that we think and there may well be benefits.

Although seemingly archaic it's nature is to 'physically' describe piece movement from the perspective of the player on the move. When thinking about moves internally it makes perfect sense to me. The internal picture builds up like a natural spoken language as opposed to a more mnemonic style thought process.

It seems long winded now, for sure, but then more colourful languages do tend to be appear that way compared to more stripped down and 'logical' forms I wonder?

Jun-29-11  Graham1973: The first ever match and MadHack VI's first non-loss are now available for inspection. Hopefully that first ever (& only?) win will join them soon.
May-14-13  Graham1973: Have tried to convert MadHak VIs first win.

Game stops at third move.

Here is the escriptive notation. If anyone can help...?

1. P-K4 P-QB4
2. P-Q4 PxP
3. QxP N-QB3
4. Q-Q3 N-B3
5. N-QB3 P-KN3
6. N-KB3 P-Q3
7. B-KB3 P-K4
8. B-KN3 P-QR3
9. O-O-O P-QN4
10. P-QR4 P-R3
11. K-QN1 P-N5
12. QXP/Q6 B-Q2
13. B-KR4 B-N2
14. N-Q5 NXKP
15. N-QB7 QXN
16. QXQ N-B4
17. Q-Q6 B-KB1
18. Q-Q5 R-B1
19. NXKP B-K3
20. QXN! RXQ
21. R-Q8

My source was:

May-18-13  Tomlinsky: Here you go <graham1973>. 12.Qxd6 is somewhat strange, regardless of hardware and horizons, and the response 12..Bd7 even more mystifying. I expected some moves to be missing but the following moves bear out that score appears to be accurate.

Anyway, that's what the score says...

[Event "Massachusetts State Championship 1967"]
[Round "3"]
[White "Mac Hack VI"]
[Black "1510"]
[Result "1-0"]

1. e4 c5 2. d4 cxd4 3. Qxd4 Nc6 4. Qd3 Nf6 5. Nc3 g6 6. Nf3 d6 7. Bf4 e5 8. Bg3 a6 9. O-O-O b5 10. a3 h6 11. Kb1 b4 12. Qxd6 Bd7 13. Bh4 Bg7 14. Nd5 Nxe4 15. Nc7+ Qxc7 16. Qxc7 Nc5 17. Qd6 Bf8 18. Qd5 Rc8 19. Nxe5 Be6 20. Qxc6+ Rxc6 21. Rd8# *

May-18-13  Graham1973: Thanks,

I'll test it out and then see about uploading. Will change the name of White to Greenblatt (Computer) when I do.

May-19-13  Graham1973: Game worked out. Uploaded. Changed player of White to "Greenblatt(computer)" and name of Black to "NN".

I think (Though I'm not sure.) that the game is the first time that software beat a ranked player.

Oct-26-15  zanzibar: Does anybody have the game Mac Hack played against John Curdo in 1971?

See CN #5634,

Premium Chessgames Member
  MissScarlett: <BobCrisp: Is <Greenblatt> a Jewish name?>

A pointed question. Yes, 1977 was surely the last year that Fischer would've played such a match. By 1978, he would likely have dubbed the program <satanic>.

Premium Chessgames Member
  MissScarlett: <Does anybody have the game Mac Hack played against John Curdo in 1971?>

You will, at <sargon>'s leisure.

Premium Chessgames Member
  AylerKupp: Why does everyone keep referring to this program as the "Greenblatt program"? The name of the program that Richard Greenblatt wrote is MacHack VI' "MAC" because he wrote it as part of Project MAC at MIT, "Hack" because he considered himself a hacker (in the days when "hacker" had a different connotation than it does today), and "VI" because it was originally written to run on a PDP 6.

After all, we don't refer to Stockfish as the "Romstad Program" (even though it was written in collaboration with others and is today supported by many others), Rybka the "Rajlich Program" (although he also wrote Fritz so if both programs' names were changed that would certainly cause confusion), Houdini the "Houdard Program", Komodo the "Dailey Program" (although he was supported by others), etc. So why continue to call MakHack VI the "Greenblatt Program"?

And "Greenblatt (Computer)" is even worse. I don't think that Greenblatt ever refer to himself as a computer, but I might be wrong on that one.

Some features of the MackHack VI program that have not been mentioned:

1. It played its first tournament in Feb 1967 and was rated about 1400 in May 1967. It was estimated to be rated about 1600 in 1967.

2. It was the first chess program to defeat a human in tournament play, Ben Landy (rated 1510) in the 1967 Massachusetts State Championship.

3. It was the first chess program to incorporate a hash table to speed up search tree position evaluations.

4. It was the first computer chess program to be widely distributed.

5. In addition to the usual minimax evaluations and alpha-beta search tree pruning, it incorporated about 50 heuristics to prune its search tree and allow it to search deeper. Father of Stockfish?

6. It contained an opening book compiled by Larry Kaufman (one of the main current Komodo developers) and Alan Baisley.

7. The final versions had about 256 KB RAM (a lot in those days), although the early competition versions only had 16 KB RAM.

8. It (interestingly, I think) evaluated material in centipawns as follows: Pawn = 100, Knight = 325, Bishop = 350, Rook = 500, Queen = 975, King = 1,200. So I would suppose that it would rather get mated than give up its queen and a rook (K = 1,200, Q+R = 1,475) ???

Premium Chessgames Member
  diceman: <AylerKupp:

Why does everyone keep referring to this program as the "Greenblatt program"?>

Because the top of the page says this:
<Greenblatt (Computer)> :)

Premium Chessgames Member
  AylerKupp: <diceman> I suppose that's as good an answer as any, and better than most.
Oct-15-18  nok: <After all, we don't refer to Stockfish as the "Romstad Program" (...), Rybka the "Rajlich Program">

Indeed, it's the "Letouzey Program".

Premium Chessgames Member
  HeMateMe: Greenblatt was the name of the programmer. He could name it anything he wanted to, I guess. What sounds better, Microsoft or Gates-Allen? "Gallen"? "Greenblatt" has a nice ring to it.

He's immortalized, as his baby is overwhelmed by a reclusive genius, in one of the early games between a (reasonably) strong chess program and a top grandmaster.

Premium Chessgames Member
  AylerKupp: <<nok> Indeed, it's the "Letouzey Program".>

Perhaps. Rybka was certainly "inspired" by Fruit or whatever euphemism you want to use. But the version of Rybka that relied heavily on Fruit was version 2.3.2a which was released in June 2007 and was the version "investigated" by the ICGA. The version sold in 2012 at the time of the investigation was version 4.1 which was released in March 2011. This version was considerably stronger than Rybka 2.3.2a and its code contained very few similarities to the code in Rybka 2.3.a.

The ICGA's investigation was "officially" motivated by their originality rule (rule 2) for the ICGA's so-called "World Computer Chess Championship". The rule requires that "Each program must be the original work of the entering developers. Programming teams whose code is derived from or including game-playing code written by others must name all other authors, or the source of such code, in their submission details. Programs which are discovered to be close derivatives of others (e.g., by playing nearly all moves the same), may be declared invalid by the Tournament Director after seeking expert advice. For this purpose a listing of all game-related code running on the system must be available on demand to the Tournament Director."

This rule, in my opinion as a career software developer and the opinion of many others, is unenforceable. At what point does the need to be original apply? Are chess programs prohibited from using minimax, heuristics, alpha-beta pruning, hash tables, etc. because these did not originate with the program's developers, particularly when the algorithms used have been published, in the public domain (like Fruit), and not considered trade secrets? And how is the fact that two programs play the same moves an indication that one program is a close derivative of others? Does that apply to the 1...c5 response to 1.e4?

The fact is that <all> software is "inspired" by previously developed software or algorithms. And the ICGA never explained how a "copy" of another program can play chess significantly better than the supposed source of its code.

Premium Chessgames Member
  AylerKupp: <<HeMateMe> Greenblatt was the name of the programmer. He could name it anything he wanted to, I guess.>

Yes, Richard Greenblatt was the programmer. And he chose to call the program MacHack VI. It's other people who chose to call it the "Greenblatt Program", not him.

Premium Chessgames Member
  HeMateMe: I think he should file a law suit.
Premium Chessgames Member
  AylerKupp: <HeMateMe> I agree. During my career I wrote many bad programs and I would have hated to have my name associated with any of them. Thankfully that never happened. And to think that I got paid for writing them anyway!
Premium Chessgames Member
  HeMateMe: Well, isn't it kind of nice to be immortalized with bobby Fischer?
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