It is a good idea to play over your games, win or lose. You can pick up tactical tricks that you missed during the contest. You can learn more about your openings and prepare for the next time they show up on the board.
The following game is a good example. Bill's experience with the Jerome Gambit is significant, and his experience with the particular defense that his opponent constructed means that the number of moves that were "new" was quite small.
Wall, Bill - MYGZ
FICS, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+
4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bb4+
This is a reasonable way to deal with White's pawn fork: Black will move one piece and return the other for a pawn. The Database has 314 game examples; White scores 57%. (Since there are 2,018 games with the position after 6.d4, where White scores 55%, Black's choice in this game - from a practical point of view - is, if anything, better than average.)
7.c3 Bxc3+
Bill has already seen 7...Be7 8.dxe5 Nh6 9.Qf3+ Ke6 10.Bxh6 gxh6 11.Qf5 checkmate, Wall, Bill - ChrSav, FICS, 2010.
8.Nxc3 Ng6
Instead, 8...Nc6 was seen in Wall, Bill - Caynaboos, FICS, 2011 (1-0, 26) and Wall, Bill - ChessFlower, PlayChess.com, 2012 (1-0, 27).
9.O-O Nf6
Black tried 9...N8e7 in Wall, Bill - NN, lichess.org, 2016 (1-0, 18) and Wall, Bill - Jamato, lichess.org, 2017 (1-0, 55).
10.e5
An improvement over 10.Bg5, as in Wall, Bill - Shatskov, lichess.org, 2016 (1-0, 16).
10...Ne8
No more effective was 10...Ng8, seen in Wall, Bill - Guest2372880, lichess.org, 2018: 11.f4 d6 12.e6+ Bxe6 13.f5 Bxf5 14.Rxf5+ Nf6 15.Qb3+ Ke8 16.Bg5 Rf8 17.Re1+ Ne7 18.Bxf6 Rxf6 19.Rxf6 gxf6 20.Nd5 f5 21.Nxe7 Qxe7 22.Qg8+ Kd7 23.Rxe7+ Kxe7 24.Qxa8 Black resigned
11.f4
Stronger than 11.Qf3+, seen in Wall, Bill - Boris, SparkChess.com, 2012 (1-0, 31).
11...Rf8
12.f5 Ne7
This loses quickly, but the "best" move, 12...Kg8, just tosses a piece.
13.Qb3+ d5 14.exd6+
Here, Black resigned in Wall, Bill - FJBS, FICS, 2015.
14...Kf6 15.Ne4 checkmate
