Over/Under Betting in Tennis

I haven't been betting tennis that long, but something caught my eye and I was hoping for some input since many of you have been betting tennis for a long time.   What I noticed was that a lot of the time the over/under lines don't change a lot even when there is a big fave compares to a match that is considered a toss-up.   For example, today at my book I have:   Pennetta +104 vs. Wazniackia -113 Over 22.5 -110 Under 22.5 -106   Querrey -316 vs. Acasuso +285 Over 22.5 +100 Under 22.5 -116   Verdasco -310 vs. Andreev +279 Over 22.5 -109 Under 22.5 -107   The first match is nearly a toss-up, while the 2nd and 3rd have very large faves. However, all the Over/Unders are at 22.5 and there isn't a significant difference in the juice.   This would suggest to me that it might be profitable to look at the "Over" in matches that are considered toss-ups and look at the "Under" in matches with a large fave.   I know this is nothing groundbreaking, but I really thought that in matches with two evenly matched players you would see a much higher Over/Under than you would in matches where one player is considered significantly better.....after all, you would think a 50/50 match would have a much better chance at going to 3 sets than a match in which there is a large fave. It really surprised me that the lines do not suggest this.   Does anyone have any thoughts on this?... [More]