I recall the phrase, but quite honestly it's been a while since I read it in context...

Math is not a competition. The only game comparable to it is solitaire. But the winning state of solitaire is the same every time- nothing left.

Games are many things, and it would be incorrect to surmise that a game must have competition necessarily. For example, some people play word games, yet they may not be competition, just having fun with words.

The winning states of math are solutions, theorems, theories and other results that can be used for more gaming. If it's a game, it's the best one going.

I guess it all depends on what games you like to play. Don't you like card games? Although, mathematicians are paid to play a game, so I guess in that sense it's a pretty good game to be good at.