This game aside, his defense isn’t very good. He’s allowing a 47.7% FG%, worst among rotation players on our team. He’s the only rotation guy on our team who allows opponents to shoot better than their normal percentage. He ranks in roughly the bottom 20% of starters in terms of FG% differential (what opponents normally shoot vs. what they shoot when covered by Kyrie).
Since Christmas, he’s allowed 50.9% shooting.
https://stats.nba.com/players/defense-dash-overall/?Season=2017-18&SeasonType=Regular%20Season&sort=PCT_PLUSMINUS&dir=1&CF=PLAYER_LAST_TEAM_ABBREVIATION*E*Bos:GP*GE*10&DateFrom=12%2F25%2F2017&DateTo=02%2F24%2F2018
Looking at those post-Christmas stats, it seems like everybody is doing his job well except for Kyrie (and Monroe, which is understandable). Horford and Smart in particular have been defensive beasts.
Good stats, but we need a bit more context.
For instance, other guards in the league that allow a bigger differential than Irving are Murray, Rubio, Hield, Hood, Burks, Schroeder, Russell, Fournier, KCP, Oubre, Stephenson, Jackson, Teague, Rondo, Smith, Booker, Parker, Barton, and STEPHEN CURRY.
Clarkson, Payton, Brogdon, Bradley, Delly, Paul, Rivers, and Hill all allow a positive point differential also.
You can't only look at the percentage of makes. You also need to look at the number of shots allowed by Irving. Irving is allowing the 38th most field goal attempts per game among guards who have played at least 30 games. There could be many reasons for that, but one possibility is that Irving is forcing the ball out of the his man's hands.
Players that allow more field goal attempts per game and a higher percentage than Irving include Payton, Smith, Schroeder, Dunn, Booker, Murray, Fournier, Teague, and Barton.
This is not adjusted on a per36 minute basis, because I don't feel like doing that right now. It does, however, give more context to the numbers you presented.