Last time I took this bet with similar reasoning:
First two games were blowouts, other two pretty strange with Memphis playing very well. But they all had something in common - few steals. I expect harder defense this time and more TO's as tension grows. And the fifth game finally went over 13 steals, even with Kawhi getting only one and both teams 16 TOs in total. That numbers will rise tonight, I'm pretty sure.
As stakes for both teams are even bigger, SAS can not let the series go to seventh game and it's a do-or-die game for Memphis.
Season averages - Grizzlies 8.0, Spurs 8.0
And the odds are even better, as public seem to go the other way.