2008 World Championship

Pre-Tournament

Twenty-six players have registered for the 2008 Arimaa World Championship, up from twenty last year, setting a new record for participation. Nine countries are represented, down from ten last year, and Asia is again under-represented. Ten of the players this year are relatives of Omar, the inventor of Arimaa, so this tournament will be much more of a family feud than in years past. Notably this is Aamir's first World Championship, the Aamir for whom Arimaa is named.

Twelve of this year's players also participated in last year's championship, an increase from nine returning players then. Retention remains high. The average increase in rating among the returning players is 107 points. This is quite similar to the 119-point year-on-year increase for returning players between 2006 and 2007. Since the ratings of constant-strength computer players aren't obviously inflating as well, the increase of about 100 points per year in human ratings probably reflects a continuing increase in human understanding of Arimaa.

Each of the four previous World Champions (Belbo, Fritzlein, robinson, and chessandgo) learned the game within a year of taking the title. Belbo and robinson are not playing this year, but perhaps one of chessandgo and Fritzlein, the top two seeds, will become the first repeat champion. Or will history repeat itself in a different way by crowning a newcomer champion? This year the highest-rated newcomer is mistre, the ninth seed.

Even if a newcomer doesn't win, the champion need not be one of the previous title holders. PMertens finished third in 2006 and second in 2007. His upward trajectory is clear. Also 99of9, naveed, and omar bring valuable experience to the table; each has played in every Arimaa World Championship so far. Keep an eye out for Adanac, runner up in 2006; he has played more training games in recent weeks than anyone.

This year's tournament will be Swiss paired for six rounds instead of being an elimination tournament from the start. The greater number of players and the new format insure there will be about 95 games played, compared to the 40 games in the 2007 World Championship. Everyone is guaranteed six games regardless of results, and the Swiss pairing should make for many competitive games after the obligatory early-round blowouts. In the last two rounds especially, every game should be a nearly equal match.

After six rounds, the top eight players will have their losses forgiven, and enter a double-elimination final for approximately six more rounds. At a pace of one round per week, it should be near the end of March when the 2008 Arimaa World Champion is crowned.

To be in the top eight after six rounds will certainly require four wins. Will it require more? There might be eight, nine, or ten players with at least four wins. The tiebreaker, if necessary, to determine who advances to the finals, is the number of wins scored by opponents, i.e. strength of schedule. In a Swiss-paired tournament I always root for my opponents to do well, starting after I have played them. The coveted top seed into the finals automatically goes to the player who manages to win all six preliminary rounds, or if no one does, to the one-loss player who played the toughest opponents.

The most exciting thing about the upcoming tournament is that so far nobody truly understands how to play Arimaa. The simple question of whether it is advantageous or disadvantageous to advance horses in the opening is still unanswered. Surely it depends on the situation, but we don't know much more than that. Anything can happen in any given game.

• 2008 Open Classic Round 1
• 2008 Open Classic Round 2
• 2008 Open Classic Round 3
• 2008 Open Classic Round 4
• 2008 Open Classic Round 5
• 2008 Open Classic Round 6
• 2008 World Championship Finals

Results

Open Classic

Seed	Participant	Rd. 1	Rd. 2	Rd. 3	Rd. 4	Rd. 5	Rd. 6	Wins	SoS
1	chessandgo	S 14 W	S 7 W	G 3 W	G 13 W	S 2 L	S 6 W	5	22
2	Fritzlein	S 15 W	G 8 W	G 6 W	S 4 W	G 1 W	S 3 W	6	25
3	99of9	G 16 W	S 9 W	S 1 L	G 10 W	G 7 W	G 2 L	4	23
4	Adanac	S 17 W	S 10 W	G 5 W	G 2 L	G 12 W	S 7 W	5	19
5	PMertens	G 18 W	G 11 W	S 4 L	G 12 L	Wthdr	Wthdr	2	12
6	arimaa master	S 19 W	G 12 W	S 2 L	S 9 W	G 13 W	G 1 L	4	24
7	jdb	S 20 W	G 1 L	S 15 W	G 16 W	S 3 L	G 4 L	3	21
8	naveed	G 21 W	S 2 L	S 16 L	G 24 W	G 10 W	S 12 W	4	20
9	mistre	S 22 W	G 3 L	S 17 W	G 6 L	G 11 L	G 21 W	3	18
10	Arif_Syed	S 23 W	G 4 L	G 19 W	S 3 L	S 8 L	G 17 W	3	20
11	omar	G 24 W	S 5 L	S 13 L	G 19 W	S 9 W	S 15 W	4	18
12	camelback	G 25 W	S 6 L	G 26 W	S 5 W	S 4 L	G 8 L	3	18
13	woh	S 26 W	G 14 W	G 11 W	S 1 L	S 6 L	G 16 W	4	19
14	megamau	G 1 L	S 13 L	S 24 L	G 23 L	S 25 W	S 20 DF	1	16
15	fritzlforpresident	G 2 L	S 21 W	G 7 L	S 22 W	S 26 W	G 11 L	3	19
16	froody	S 3 L	G 22 W	G 8 W	S 7 L	G 17 W	S 13 L	3	19
17	ChrisB	G 4 L	S 23 W	G 9 L	G 20 W	S 16 L	S 10 L	2	17
18	zackry	S 5 L	S 24 L	G 22 L	S 25 L	Wthdr	Wthdr	0	8
19	Aamir	G 6 L	S 25 W	S 10 L	S 11 L	G 24 W	G 22 W	3	17
20	Fisma	G 7 L	G 26 L	S 23 W	S 17 L	S 22 L	G 14 DF	1	12
21	silump5	S 8 L	G 15 L	G 25 W	S 26 L	G 23 W	S 9 L	2	15
22	Amina	G 9 L	S 16 L	S 18 W	G 15 L	G 20 W	S 19 L	2	13
23	soldier	G 10 L	G 17 L	G 20 L	S 14 W	S 21 L	G 25 W	2	10
24	subs2000	S 11 L	G 18 W	G 14 W	S 8 L	S 19 L	G 26 W	3	14
25	Sana	S 12 L	G 19 L	S 21 L	G 18 W	G 14 L	S 23 L	1	11
26	Emaad	G 13 L	S 20 W	S 12 L	G 21 W	G 15 L	S 24 L	2	16

Finals

Seed	Participant	Rd. 1	Rd. 2	Rd. 3	Rd. 4	Rd. 5	W-L	Finish
1	Fritzlein	G 8 W	S 5 W	G 2 W	S 3 W	G 2 W	5-0	1st
2	chessandgo	G 7 W	S 3 W	S 1 L	G 4 W	S 1 L	3-2	2nd
3	Adanac	G 6 W	G 2 L	S 5 W	G 1 L	S 4 W	3-2	3rd
4	arimaa master	S 5 L	G 8 W	G 6 W	S 2 L	G 3 L	2-3	4th
5	99of9	G 4 W	G 1 L	G 3 L			1-2	t5th
6	naveed	S 3 L	G 7 W	S 4 L			1-2	t5th
7	woh	S 2 L	S 6 L				0-2	t7th
8	omar	S 1 L	S 4 L				0-2	t7th