I'm refering to the winning streak in the games section that is listed under "My stats".
draw in winning streak?

I can personally attest that a draw cuts your winning streak short. In the last ~50 games, I have drawn two and won ~48, but my longest winning streak was interrupted by the first of those draws.
So yeah, I'd like to see a "longest undefeated streak" in the stats too...
If one is going for a personal best winning streak, does a drawn game automatically end it or would it continue? Just curious if anyone knows.