Thursday, January 14, 2016

Quick math for S.C.- can you "jack" net rating with Free Throws

In a thread at FeartheSword commenter S.C. complains that FTs late in a Boston game can cause net rating to get "jacked".  Is this plausible?

In the game under discussion the Celtics had a 1 pt lead with about 1 min to play and ended up winning by 9 in part thanks to desperation fouling.  How much could this effect net rtg over the course of a season?  Well 8 pts over 82 games is worth less than 0.1 pts in final differential, so for a team to experience a substantial increase in their net rtg due to circumstances like these they would need 10+ events worth 8 pts to give them a fake improvement of a full point.  Of course this assumes that they are never on the other end of the scenario, so they need to be on the winning side 10 more times than the losing to gain a full point.  Even if they were very good/lucky and had a 2:1 ratio in their favor they would need to play 30 games a year that ended with desperation fouling.  Not particularly plausible.

How about the 8 pt swing?  Is that plausible?  Well, no.  Only 4 of those 8 pts were due to desperation fouling, the Celtics and Pacers had "normal" possessions until the Pacers missed a shot with 29 seconds left and started fouling.  Realistically for a team to jack their net rating by +1 due to these games they would have to play them 60 times a year, and be on the winning side at a 2:1 ratio.

There are also lots of other potentially odd situations late in games that "effect" net rating,  large leads where one team pulls its starters before the other, and teams dribbling out the clock and not working for a shot generally push back in the other direction.  Anyway you look at it though it is very hard for these things to substantially alter a full seasons play because they are not common enough nor are they perpetually one sided. 

Saturday, January 9, 2016

Lebron's decline?

Seth Partnow has a piece up at the Washington Post where he argues that Lebron has entered his physical decline and cites two (damning) pieces of evidence.  First that Lebron is getting blocked at the rim at a much higher rate the past two seasons (9.4% of the time this year vs 5.2% his final year in Miami) and his FG% at the rim has declined EVEN when ignoring those blocked shots.  I will add in a 3rd piece of evidence, his FT rate is the 2nd lowest of his career, ahead only of his sophomore season, and 5-6 percentage points below his time with Miami.  If that is the only evidence available it certainly seems inarguable that Lebron's physical prime is behind him.

There are some encouraging signs in the opposite direction.  While Lebron is finishing at the rim at a substantially worse rate, he is getting to the rim better than at any other point in his career.  According to Basketball-Reference Lebron has taken 43.5% of his shots inside of 3 ft so far this year, substantially above his 2nd best year of 39.9% and miles better than his career average of 34.3%.  He is also taking a few extra shots from between 3 and 10 ft, 13.6% vs career average of 12.2% and his 3pt rate is right around his career average, which means these extra close 2s are all coming at the expense of shots from 10 ft out to the 3 pt line, the easiest shot in the league to take, and the least valuable. 

This is not a compositional change either where Lebron is passing out of long 2s and so his percentages from other spots rise as a result of lower usage.  James' usg, at 32.9 after last nights game, is the highest it has been since he left Cleveland for Miami and his turnover rate is the 2nd lowest of the past 6 seasons.  Meanwhile a couple of other indicators of athletic ability, steal and block percentages, are right at his career average. 

So far this season James' decline in efficiency at the rim, combined with his worst 3 pt shooting season and a below average FT% have overwhelmed his large improvement in shot selection (for lack of a better term).  Considering that he has finished the last 7 years at 33% or above from 3 and the last 4 years above 35% it is highly unlikely that he has suddenly become Josh Smith bad at 3 pt shooting. 

In conclusion Seth Partnow is probably correct that Lebron has entered into his "decline", but his numbers are an exaggeration of that decline without the proper context.  Lebron's decline is likely to be gradual, and at times almost imperceptible, which is not at all unprecedented as other NBA greats like Kobe, Duncan, Jordan and (especially) Karl Malone have managed to fight off aging to varying degrees. 

Thursday, January 7, 2016

Narrative vs reality

I'm a Cavs fan, and I watch Cavs games.  Last night Kyrie and Lebron were great, getting to the rim, spectacular finishes, nailing outside shots.  The narrative from a game like this is that the Wizards couldn't keep up with the Cavs 2 big scorers (sorry Kevin Love).  But they actually did.  The Wizards earned 8 more FTs than the Cavs, made 2 more 3s on 5 fewer attempts, and had a higher FG%, eFG%, and TS% than the Cavs.  In terms of "ball movement" Washington DOUBLED the Cavs assist % and almost doubled their assist total (31 to 16). 

How did the Cavs win, and win fairly handily as Cleveland's lead was between 8 and 14 points from 8:43 remaining until Wall hit a 3 with 2.9 seconds remaining to make the final score more respectable, when Washington was more efficient by most metrics?  Well Gortat, Porter and Dudley combined for 5 offensive rebounds, and the rest of the Wizards combined for zero.  On the Cavs side Love had 5 0-boards on his own.  Dellavedova had as many offensive rebounds (3) in 28 mins as John Wall had total rebounds in 40 mins. 

That the Cavs out rebounded the Wizards is unsurprising.  Cleveland is 3rd and 7th in D and O rebounding rates and the Wizards are 15th and 26th, but that the Cavs could do it while playing a 7 man rotation that consisted of 4 guards under 6'6?  While Mozgov played only 4.5 mins?  This game further reinforces my belief that the single biggest edge that Cleveland has is in its ability to field 3 or 4 + rebounders at a time, even when they are playing "small".