One of the things I tried to do before posting this was try and find empirical data that proved that timeouts stop momentum. I couldn't find any. The closest I found was this:
Does Calling Timeout Actually Help?
Updated May 31, 2012 9:01 pm ET
In the NBA, calling a timeout to slow the opposition's momentum is such a fundamental tactic that even the woeful Charlotte Bobcats managed not to get it wrong this season. But here's the thing about timeouts: New research is challenging the notion that they have a significant effect on the final outcome of games.
In a recent study, three Northwestern University researchers analyzed the time and score scenarios of every timeout called by all 30 NBA teams over the last three seasons. They started with the hypothesis that timeouts do, in fact, change games. From there they focused on the score differential between timeouts and compared it to the expected score differential if timeouts were randomized.
What they found surprised them: Timeouts had no significant effect in 68 of the 90 cases. Over a full game, their research shows, the better team still usually won.
Granted, no one is expecting Spurs coach Gregg Popovich (above) and the other remaining coaches in the NBA playoffs to stop trying to use timeouts strategically. Not only are timeouts practical and potentially inspiring—"I need a little bit more dose of nasty," Popovich urged the Spurs during their Game 1 win over the Thunder this week—but the Heat, Thunder and Spurs are also exceptions to the rule. The study found that the handful of teams for whom timeouts were significant were often the best and worst in the NBA.
The only team that used timeouts better than those three? That would be the Indiana Pacers, who lost to the Heat last round.
Ben Cohen
https://www.wsj.com/articles/SB10001424052702303640104577438322344613742
Now this is one of those things where people fundamentally believe one way or another and no empirical data or lack thereof will cause them to change their mind. Kind of like sabermetrics vs "going with your gut". But if I had to try to find a reason why they would work, I suspect it would be because the team has lost focus or lost sight of the fundamentals they are supposed to execute and the timeout allows the coach to remind them to reset themselves, get back to the plan and after the timeout they are able to do that. Kind of like people saying "well we need halftime to regroup."
A run happens when one team starts making shots and one team starts missing. The team missing shots could be doing so because they started deviating from the game plan, going iso, stopping passing the ball, or stopping communicating on defense, going under screens instead of switching, etc. Or they could be doing the right things, taking good shots, and just missing. In the former calling timeout makes sense so the coach can remind them to get back to the game plan. But if they are doing the right things and just missing and the other team is making their shots, is it truly helpful purely as a tool to disrupt the other team's momentum?
I think what Joe is trying to do, which a lot of coaches probably would like to do, is to put the players through those experiences where they take responsibility themselves for getting themselves back on track, starting to execute fundamentals properly, calling switches, finding simple PnR plays to get their offense going again. Rather than him calling a timeout and telling them to do those things.
I feel like it's also his style - he's more of a coaching personality than a coercive one, probably because he's coming into a situation where he has no NBA coaching experience, he is technically interim, and he's coaching a team that went to the NBA finals. If we had hired Pop or D'Antoni or even Stan Van Gundy I think they would be much quicker to blow the whistle and impose themselves on the game. I think Joe is willing to do that, but he's trying to empower them rather than be an authoritarian, especially if he thinks they are doing the right things anyway and are just on the wrong end of the scoreboard.
Obviously as fans we panic and scream at the TV when the lead dwindles, but I don't think the players do, or Joe