1) According to the NFL: traditionally YAC is measured by taking the difference between the yards gained and the air yards of a completed pass.

This means that catching the ball 5 yards behind the LOS and advancing to 5 yards beyond the LOS is 5 yards of YAC - not 10. It is also*5 yards gained for the QB (air yards = 0).

In the current version of FB Mogul, RBs and FBs often have YAC > yards per catch - which is not possible given the definition of YAC.

2) The calculation of yard per catch appears to be off by a small amount. 33 passes caught for 333 yards is 10.1 yards per completion. Sortable stats displays it as 10.4.