Too many fields in MySQL?

Question

I developed a stats site for a game as a learning project a few years back. It's still used today and I'd like to get it cleaned up a bit.

The database is one area that needs improvement. I have a table for the game statistics, which has GameID, PlayerID, Kills, Deaths, DamageDealt, DamageTaken, etc. In total, there are about 50 fields in that single table and many more that could be added in the future. At what point are there too many fields? It currently has 57,341 rows and is 153.6 MiB by itself.

I also have a few fields that stores arrays in a BLOB in this same table. An example of the array is Player vs Player matchups. The array stores how many times that player killed another player in the game. These are the bigger fields in filesize. Is storing an array in a BLOB advised?

The array looks like:

        [Killed] => Array
            (
                [SomeDude] => 13
                [GameGuy] => 10
                [AnotherPlayer] => 8
                [YetAnother] => 7
                [BestPlayer] => 3
                [APlayer] => 9
                [WorstPlayer] => 2
            )

These tend to not exceed more than 10 players.

Answer 1

I prefer to not have one table with an undetermined number of columns (with more to come) but rather to have an associated table of labels and values, so each user has an id and you use that id as a key into the table of labels and values. That way you only store the data you need per user. I believe this approach is called EAV (as per Triztian's comment) and it's how medical databases are kept, since there are SO many potential fields for an individual patient, even while any given patient only has a very small number of those fields with actual data.

so, you'd have

user:
id | username | some_other_required_field

user_data:
id | user_id | label | value

Now you can have as many or as few user_data rows as you need per user.

[Edit]

As to your array, I would treat this with a relational table as well. Something like:

player_interraction:
id | player_id | player_id | interraction_type

here you would store the two players who had an interaction and what type of interaction it was.