Mandatory Credit: David Richard-USA TODAY Sports

Yesterday, I looked at NBA refs and the rate that they call technical fouls.  Today, I’m looking at which refs tend to call more charges and which refs tend to call more blocks.  I only looked at refs that refereed at least 45 games to make sure there was a decent sample size of charges and blocks.  Basically the intuition of sample size is that in one game a ref might call seven charges and one block — and if all the data you have is that one game, then your data is skewed.  But if you have data from over the course of a season (or 45 games) your data does not end up being skewed.

(In case you’re curious…here’s the data source: http://vorped.com/bball/index.php/referee).

The charge-block ratio is basically the rate at which refs call charges relative to the rate at which refs call blocks.  For example, Scott Forster has a very high charge to block ratio of 10.25.  This means that this season he has called 10.25 times as many charges than blocks.  Dick Bavetta on the other hand has a charge to block ratio of 1.8.  This means that Bavetta has called 1.8 times as many charges than blocks.

What is astonishing is that only one NBA ref that has refereed at least 45 games calls more blocks than charges.  That ref would be Tony Brothers, who has a charge to block ratio of 0.889.  This suggests that experienced NBA refs tend to call more charges than blocks, in general — that’s why the average charge to block ratio is 2.41.

Some things of interest:

• While Joey Crawford has gotten a reputation for calling a lot of technical fouls,  Joey Crawford has given out technical fouls at a rate below the league average this year.