Unannounced Battle Engine Changes in Speed?

#1
I've noticed that simulator results seem to have changed recently on Speed, particularly when it comes to simming larger fleets. Results now seem to favor the defender to a greater degree than they did before, although ACS results appear unaffected (at least as far as the simulator is concerned). Have other noticed this as well?

Zorg, has there been an unannounced change to the battle engine? Some explanation for the sudden change in simulator results would be appreciated, in any event. Thanks!