Author: Pham Hong Nguyen
Date: 18:00:49 07/23/02
Go up one level in this thread
On July 23, 2002 at 18:28:38, Dann Corbit wrote: >On July 23, 2002 at 17:48:09, Shane Hudson wrote: > >>On July 23, 2002 at 03:11:17, Dann Corbit wrote: >> >>>On July 23, 2002 at 03:04:39, Pham Hong Nguyen wrote: >>> >>>>Hey Dann, I did not say about your test set - yes, all games of that test set >>>>were artificially created to illustrate how important underpromotions are. >>>>However, I am mentioning about _real_ games - other story. >>> >>>Almost all of those positions I posted are from *REAL GAMES*. Only a very tiny >>>fraction are made up positions. >>> >>>>If you or someone could (or I will do when I have spare time), do a small >>>>research about underpromotions in real games (of any database): count and report >>>>total number of underpromotions / total number of promotions. The statistics >>>>will help us on decision of design. >>> >>>The amount of useful underpromotions in real games will definitely be higher >>>than you think. If it is as small as one in a million games where >>>underpromotion provides benefit, I will be utterly astonished. >> >>I investigated this once for the purpose of improving material and >>position search times in my database app Scid. >> >>Here are stats on the number of games containing a promotion to each >>type of piece in a database of 594,803 mostly master-level games: >> >>Piece Games Freq per 1000 games >>------------------------------------- >>Any 24747 41.61 >> Q 24083 40.50 >> N 506 0.85 >> R 227 0.38 >> B 72 0.12 >>------------------------------------- >> >>Whether many of those promotions to Rook or Bishop were actually >>useful (superior to a Queen promotion) is anyone's guess. I suspect >>most occurred in situations where the piece will immediately get >>taken anyway. > >In a database of 1.7 million games with players of 2000 ELO+, I found 3056 >underpromotions. You all have excellent data. Dann, could you continue to check Shane Hudson' idea: if those underpromotions are really necessary (if not, lose or draw) or just because they will be taken on next move?
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