Watch the first quarter and see how it goes. Don't watch the second quarter. Their performance in each quarter will tell you whether or not they are better or worse with you watching. You may alternatively just follow on the radio and see if it is just vision affecting the Spurs or your auditory senses as well. If they lose when you listen, then try watching without the sound or another alternative, simply following a boxscore online. You should know in time for all important Game 4 - important to go up 3/1 if the Spurs win and important to tie and regain homecourt if they lose.

Good luck! I've found that a certain cheer while bouncing on my exercise ball produces favorable results 84.5% of the time, so I feel you.