Chess (Macintosh)

The only game bundled with Mac OS X, aside from the Tile Game found in the Dashboard.

Debug Menu
Converting MainMenu.nib to a .xib file with NibUnlocker and opening it with Xcode reveals a hidden debug menu in between the Window and Help menus. It is currently unknown how to make it appear in-game.

Unused Text
There are some interesting developer comments in bug.opn:

/* The various tags: !	best !?	interesting =	unusual but solid ?!	murky - meant for surprise ?	plain bad

/* Various bad first moves - don't play these! */

a2a3? e7e5! a2a4? e7e5! b1a3? e7e5! b1c3? e7e6!

/* Now, 1. b3 is an interesting and OK slow move that can be used for surprise. 1. b4 is an interesting wild move planning to put pressure on the long diagonal and hit a N on c6 with b4-b5 */

b2b3!? b2b4?!

/* 1. c3 is too committal to be used as surprise weapon, but 1. c4 is better than it looks. 1. d3 has the same problem as 1.c3: it is likely to transpose to some slow reversed system but without giving black any head aches with move orders. */

c2c3? e7e5! c2c4?! e7e5! d2d3? e7e5!

/* 1. d4 is a good, calm move which often leads to semi-blocked positions. I'm interested in seeing how well the program can be taught to handle those. */

d2d4=

/* 1. e3 can be used as a surprise weapon intending to make a reversed set up or something slow like Ng1-f3 and b2-b3. */

e2e3?! e7e5!

/* 1. e4! Best by test! */

/* Queen's fianchetto */

e2e4	b7b6?! d2d4!

/* Queen's knight - most likely to transpose */

e2e4	b8c6=

/* C-line crap lines */

e2e4	c7c5? b1c3! e2e4	c7c6? d2d4! d7d5	e4d5	c6d5	c1f4

/* The leaf - God I hate this shitty line. */

e2e4	d7d5?

/* 1... d6 - transposing to the Wall most likely, but also some independant lines. */

e2e4	d7d6=

/* I would expect the program to handle the tactics in the Kamikaze pretty well. */

e2e4	e7e5!?

/* On with the main bulk of opening theory. */

e2e4	e7e6!

/* The Dog will suit the computer well. */

e2e4	g8f6!

/* 1. f3 is simply bad but 1.f4 is a whole lot better than it looks - an interesting surprise weapon maybe. */

f2f3? e7e5! f2f4?! g8f6!

/* 1. Nf3 is a good second string first move along with 1. d4. */

g1f3=

/* The rest is just crap. */

g1h3? e7e5! g2g3? e7e5! g2g4? e7e5! h2h3? e7e5! h2h4? e7e5! h4h5	d7d5	P@g6	h7g6	h5g6	h8h1	g6f7	e8f7