Fivethirtyeight.com has the answer. Based on past conventions, they have modeled how much of a bounce is normal each day based on the beginning of the convention. Today’s trackers (Obama +8 and Obama +4) are based on T, W, and H. That is based around Wednesday which is the third day of the convention. Based on the model, Obama should have a 3.5% bounce. So the adjusted trackers are Obama +4.5 and Obama +.5. That’s good for Obama (in the pre-Palin era) but not a knockout. Normal convention bounce will peak at +6 by the end of the weekend.