Only if he wants the opposing PG to have a career night offensively. IT's skilled and a good offensive player, but he's a liability on defense. It seems like starting two defensive guards is conducive to IT scoring more points & allowing fewer. If we're playing against R Westbrook, there's no way that starting IT over Marcus is a good idea.
Interesting fact: Opposing PGs posted a lower PER against Isaiah (13. than they did against either Avery (15.6) or Smart (17..
Which probably has more to do with the fact that he mainly played against bench players, and that these types of stats tend to make poor assumptions about who's covering who
The bulk of Isaiah's minutes came at the end of halves and the 4th. In fact more of his minutes came in the 4th than any other period.
Do opposing starting PGs not play much in the 4th?
As to who was covering whom ... do you really think Isaiah was more often covering one of the other positions than the PG?
Didn't consider the increased minutes in the fourth (but thanks for assuming that I think people don't play their starting PGs then). The fact remains, though, that he's playing a significant amount of time against bench players
As for the coverage, yes, IT will always be covering the PG, but both Smart and AB are often covering another position, which makes their numbers suspect (and since you're directly comparing to th, it has a big effect)
I did not assume you think anything there. I asked a question.
According to 82games.com and NylonCalculus, Avery defended SGs about 2/3 of the time and PGs about 1/3 of the time while Marcus did the inverse, defending PGs about 2/3 of the time and SGs about 1/3.
The oppositional PG PER refers to the time they were on that position.
It's debatable just what portion of Isaiah's time was spent against 'bench' players or how much that share of time compares to the share of say, Marcus' minutes that were against bench players. A lot more study would be needed to nail that down, but I doubt it's as significant a difference as you might think. Remember, Marcus was coming off the bench for the first half of the year.
And Isaiah was getting just under 30 minutes. Given that most starting PGs on most teams are going 34-38 mpg, that means Isaiah had to overlap for most of his minutes against starters, even if he covered ALL of the opposing bench PGs minutes (which is highly doubtful).
The point of these numbers (opponent PER) isn't to form an exact comparision. PER numbers should always be taken with large grains of salt. The point is to illustrate that Isaiah being a "defensive liability" is probably a vast overstatement. Opposing PGs weren't lighting him up for personal bests.
If you look at how the team actually performed defensively in it's most-used 5-man lineups, Isaiah's presence or absence from those various units does NOT correlate with big changes in the defensive performance. In fact, his presence slightly correlates with
better defense (though the error bars are large due to the small sample size of the final 30 games).
A much bigger factor affecting the defensive performance, one that blows away whether Isaiah was on the floor, was the center position. Specifically, going 'small' with guys like Bass or JJ at the center position was generally a defensive disaster. The team performed much, MUCH better defensive so long as it had one of either Zeller or Olynyk on the floor. Especially Zeller. Size does, after all, matter up front.