Rubyflame writes "As noted on the Sensei's Library resource for the ancient Chinese boardgame Go, Tartrate, a very strong and mysterious Go player, has recently returned to the Kiseido Go Server (KGS) after a long absence. The game records can be found here. Tartrate first appeared in March, and has yet to be defeated - his identity is unknown." This intriguing story is a little reminiscent of Bobby Fischer's online chess appearances - the Go players on KGS even log their Tartrate number: "tartrate has a tartrate number of 0. If you have played a game with tartrate, your tartrate number is 1. If you have played a game with someone whose number is 1, your number is 2, and so on."