Turns out it’s a baserunning calculation issue. Reversion of replacement level to Jack Cust excluded baserunning prowess. Since Ur-Cust was a crafty 0/2 in the base theft department, and Replacement Definer Cust didn’t include that, well, -0.6 Runs x 2 equals…-1.2.
But I think we’ve all had days where we feel about 1.2 runs less than our regular level of performance.