Download Bluebush Chess

BenRedic commented:

Basic but perfectly usable chess game. Clearly inferior to Psion (1983).

Full screen 2D b/w board display is primitive but functional. Can toggle to moves list. Responsive cursor entry. 8 levels. Level 4 (accomplished) would be suitable for tournament play on a 1983 computer, taking ~2 mins per move. Time usage seems to increase in the endgame, though.

Shallow opening book only holds a couple of moves before the computer is on its own, even in common openings.

Does not seem to extend searches in tactical positions, causing tactical blunders. Likes to counter threats with threats of its own rather than defending, but stumbles if the computers threat can be refuted. For an example, see move 10 in the game below.

Does not seem to recognise 3rd repeat draws, and probably not 50 move draws either.

Does not give option for underpromotion, but board setup can be used for this. The same applies to takeback.

[White "BenRedic"]
[Black "Bluebush Chess 4 Accomplished"]
[Result "1-0"]
[ECO "C50k"]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 
    {Giouco piano}
4.O-O d6 
    {Book}
5.h3 Nf6 6.Re1 O-O 7.c3 Bd7 8.d4 exd4 9.cxd4 Bb6 10.Bg5 Nb4? 
    {Eying a fork at c2 after the queens are exchanged, but ignoring the simple refutation...}
11.a3 
    {Shoo!}
11...Na6 
    {Now the pinned knight on f6 is in trouble}
12.e5 dxe5 13.dxe5 Be6 14.Qxd8 Raxd8 15.Bxe6 
    ( 15.Bxa6 )
15...fxe6 16.exf6 gxf6 17.Bh6 Rfe8 18.Nc3 Nc5 19.Rad1 Nd3 20.Re2 Nxf2 
    {Trades two minor pieces for a rook and a pawn, which if anything favours white, especially when black is already a piece down}
21.Rxf2 Bxf2+ 22.Kxf2 Rxd1 
    {And trades rooks, leaving white with three minor pieces for a rook and two pawns into the endgame}
23.Nxd1 Rd8 24.Nc3 Rd7 25.Ne4 Kf7 26.Nc5 Rd5 27.Be3 b6 28.Nb3 c5 29.Ke2 e5 30.Nbd2 Ke6 31.Ne4 Kf5 32.Nc3 Rd7 33.Nh4+ 
    {Chases the black king back}
33...Ke6 34.g4 
    {and locks up}
34...Kf7 35.b3 
    {Just adjusting my pawns to better complement my dark squared bishop. The position is completely locked down, black has zero counterplay at this point. I can shuffle and position my pieces exactly where I want.}
35...Ke6 36.a4 a5 37.Nb5 Kf7 38.Nf5 Ke6 39.Na3 Kd5 40.Nc4 Kc6 41.Bh6 
    {Penetrating the kingside}
    ( 41.g5 {I missed this variation.} 41...fxg5 {is not possible because} 42.Nxe5+ {wins the rook} )
41...Rc7 42.Bf8 Kb7 43.Bg7 Rc6 44.Ncd6+ Kc7 45.Ne8+ Kd7 46.Nxf6+ Ke6 47.Nxh7 Rc7 48.Ng5+ Kd5 
    {My three pieces are now holding the kingside in a vice grip, and my h-pawn is going to make a home run}
49.h4 Rd7 50.h5 Rd8 51.h6 Re8 52.h7 c4 53.bxc4+ Kc5 
    ( 53...Kxc4 {is not possible because of the fork} 54.Nd6+ )
54.Ne6+ Kxc4 55.Nf8 
    {The rook is now blocked from taking my queen-to-be...}
55...Rxf8? 
    {...and decides to sac itself for a knight instead. I have no idea where this move came from.}
56.Bxf8 Kb3 57.h8=Q Kxa4 58.Qxe5 Kb3 59.Qb5+ Kc3 60.Bg7+ Kc2 61.Qb2# 1-0