Mentally not there

For year I've heard that ball players were "mentally out if" or "their head wasn't in the game" and I never really understood how you can be playing a game and not really have "your head in the game" It's no you're doing anything else at the time.

Lat night, playing in the substitute home court of Tuesday Night Ball, I was mentally not there. I don't know why, physically I was fine, didnt feel any more tired than normal. But I couldn't concentrate for more then a few seconds at a time. I knew it at the time, which made it all the more annoying, and then I would "get in the game" for a play and then just lose it. I was running in the spots, letting my guy uncontested offensive rebounds and tip them in, throwing teh ball away, probably missed 90 percent of my shots - All in all a disaster of a game

I can't really explain what happened, I just hope it doesn't happen again.