Irina Krush, U.S. Women's Chess Champion at age 15 played a simul of approximately 25 boards in Kingsport, Tennessee, in July, 1999.  In this game, 9-year-old James Hyde had chances on move 17 but didn't see them at the time.

[Event "Fun Fest 99 Simul"]
[Site "Kingsport, TN, USA"]
[Date "1999.07.17"]
[Round "-"]
[White "Krush, Irina"]
[Black "Hyde, James"]
[Result "1-0"]
 
1.e4 e6 2.d4 b5 3.Bxb5 Bb7 4.Bd3 f5 5.Nc3 Bb4 6.Qe2 Nf6 7.f3 O-O 8.e5 Nh5 9.Qf2 Be7 10.Nge2 f4 11.h4 d6 12.exd6 Bxd6 13.Bd2 Ba6 14.Bxa6 Nxa6 15.Ne4 Bb4 16.Bxb4 Nxb4 17.N2c3
{17...Qxd4! 18.Qxd4 Nxc2+ 19.Kd2 Nxd4}
17...Qb8 18.O-O-O Qb6 19.Nc5 Rfd8 20.Rhe1 Rab8 21.Nb3 Qa6 22.Kb1 Rb6 23.Re5 Ng3 24.Qd2
24...Rdb8 25.Qxf4 c5 26.dxc5 Ne2 27.Rxe2 Nxa2 28.cxb6 Nxc3+ 29.bxc3 Rxb6 30.Rd8# 1-0

GM Ron Henley is one of Irina's coaches and he also played about 25 games at once.  It was absolutely enjoyable to play him as he made friendly comments every time he came by to make his move.

[Event "Fun Fest 99 Simul"]
[Site "Kingsport, TN, USA"]
[Date "1999.07.17"]
[Round "-"]
[White "Henley, Ron"]
[Black "Hyde, Kevin J."]
[Result "1-0"]
 
1.d4 d5 2.Bg5 Bf5 3.e3 g6 4.c4 Bg7 5.Nc3 Nf6 6.Bxf6 Bxf6 7.Nxd5 Bg7 8.Nf3 O-O 9.Be2 Nd7 10.Nc3 Nf6 11.O-O c6 12.Rc1 Qc7 13.b4 Rad8 14.Qb3 Ng4 15.h3 Nf6 16.Rfd1 Qc8 17.Bf1 Ne4 18.Nxe4 Bxe4 19.Nd2 Bf5 20.d5 Be5 21.Nf3 f6 22.Nxe5 fxe5 23.dxc6 Qxc6 24.c5+ Kg7 25.b5
25...Rxd1! {26.bxc6 27.Rxc3} 26.Qxd1 Qf6 27.Qd2 Qg5 28.Qb2 Bxh3 29.f4 Qg3 30.Qxe5+ Kg8 31.c6 bxc6 32.bxc6 Bxg2 33.Bxg2 Rc8 34.Qe6+ Kg7 35.Qxe7+ Kh8 36.Qe5+ Kg8 37.Kf1   1-0