Many BGG users enjoy keeping track of the games they play (by date and number of times played). Then there are various reports you can see to observe your gaming history.
How to log plays
You can log plays from the game's individual BGG page, via the "Log Play" button (which also shows how many plays you already have logged).
You can also log plays via your own BGG collection. From the "My Geek" section at the top of your BGG profile, choose "Collection." A list of the games you own will be displayed. Choose the row for the game you want to log in and click in the cell under the "Your Plays" column, two from the right side of the screen. A dialog box will come up and you can log your play there.
You can also search for the game (via the "SEARCH Board Game" at the top of many BGG pages), then in the list of search results, click in that game's cell in the column "Your Plays" to get a popup dialog box.
Dazeysan's Splendiferous Play-Logging Utility makes it much easier to log games and their expansions.
There exist various other third party software for logging as well.
How to delete logged plays
To delete a logged play, go to any of the pages that show your logged plays (e.g. My Geek | Games Played | By Date) and then you can Edit or Delete the logged play(s).
Why log plays?
Different people log for different reasons. There are many forum threads discussing this, e.g. this one and this one. Common reasons include:
- Pure geeky statistical fun.
- See which of your games don't get played. (Perhaps as a nudge to play them - or to get rid of them.)
- See the reality of what you play, compared to people's very faulty memories of what they play.
- See how much "money's worth" or hours of playing you get out of your games.
- Keep track of wins and losses, perhaps to track one's progress or for a local group's tournament or ratings.
- Like a diary, it's enjoyable nostalgia to reread and remember old sessions.
- Comment about strategy ideas and track your evolving strategy ideas over time.
- Because you can get all kinds of statistics from your logged plays via Friendless's BGG Extended Stats Server
Policies about logged plays
There are no rules and no general consensus about questions like:
Sessions with multiple plays of a given game, e.g. playing Blokus 3 times in a row?
- Log each individual play as a play, so 3 plays logged.
- Log the session as a play, so 1 play logged.
Which types of games should I log?
- Face-to-face (almost everyone would log these)
- Played via computer with other humans
- Played via computer with other humans and AI players
- Played via computer only with AI players (most people wouldn't log these)
What date should I log a game that took more than one day?
- The day I started playing
- The day I finished playing
- Each day I played it (most people wouldn't do this)
What about expansions? (There's really no clear consensus on this question.)
- Only log base games
- Only log the expansion
- Log the expansion and the base game
- Log the base game, and use a hack to log the expansion as a fractional e.g. 0.1 or 0.01
Decide for yourself what your logging goals are and choose a personal policy accordingly. Is a game against AI players just as meaningful for you as a game against humans? Do you want your total number of plays per month to equal the number of times you played a game that month, or do you want each game and expansion to show how many times you played it? Is it easier for you to remember to log a long game the day it begins or the day it ends? Etc.
Expansions are complicated
People often propose that BGG should automatically link expansions to "the" base game they expand, so they can log the expansion and have it automatically log the base game for them. But: