DA and tuning at a different track?

UOP said
You may be running a little too rich if it continues to gain with that much timing. Are you running an a/f gauge or reading the plugs?

what do you mean by that?

plugs look good. when i was tuning the car i pulled two plugs after each pass and they seemed to look great. my question is about lv track tuning in comparison to sac where i live