Semi plays because he's committing to defense, while most of the team is not. Of late, they've made a mockery of it: https://www.youtube.com/watch?v=9MORBtzEOvQ. I would love to see the advanced defensive stats for Semi. What do opponents shoot against him? The percentages on how good is he defending the pick and roll. How good do people he is guarding shoot the three? What do people shoot against him when he defends in the paint?
For example, when George Hill and LBJ were having their way in the PnR during the 3rd quarter of Sunday's game, adjustments needed to be made -- see Semi's substitution and subsequent defensive switches (Osman).
People seem to give Brad too much credit for the amount of control he has over the team in mid- February. When your defense is struggling, playing guys that commit on that end is a way -- sometimes the only way -- to get buy-in. It's that simple.
Maybe having those stats would enlighten us on why Stevens uses Semi so much.
On shots overall, opponents are shooting 44.1% DFG% when contested by Semi. This is -1.7% below their normal FG%.
That DFG% is about the median among Celtics players, but doesn't tell you much because it doesn't break-down by shot type.
On 3PT shots, for the season, opponents are shooting 35.7% against Semi, which is -0.8% below their normal 3PT%.
On 2PT shots, for the season, opponents are shooting 48.5% against Semi, which is -2.8% below their normal 2PT%.
Unfortunately, in this particular game, Semi's opponents kinda shot the lights out, hitting 4 of 4 on threes and 7 of 9 overall against him.
But the Cavs were basically just plain red-hot and hitting all kinds of shots, including ones that were tightly or even very tightly covered.
I wouldn't read too much into this one game for either team.
The combination of our really bad shooting (despite generating a _ton_ of open & wide-open looks) and their really hot shooting (despite not really having near as many open & wide open looks) kinda hides the fact that they (Cavs) still may have some serious defensive problems. And our poor shooting on open & wide-open shots isn't necessarily anything to do with their defensive prowess.