Couldnt find any time related stats but I'm sure Tsitsi's serve game were something like 50% longer than Djoko's. He had 2 extremely disputed ones in the 3rd and 4th and he lost both after several deuces. I think the serve game he lost in the 3rd lasted 11 minutes or something. Must have been excruciating.
I put it on experience but after some time he should have tried going with accuracy rather than power on his 1st serves because his 1st serve percentage wasnt that good so he needlessly invited pressure on himself.
But I'm not too worried on this new gen. Meddy, Tsitsi and Zverev will get theirs, they have the quality, they just need consistency. Medveded lostxa 5 setter against Rafa. Tsitsi lost a 5 setter against Nole. They are close and also, they are young enough to avoid getting barred by the big 3 their whole career... Unless those 3 play until 50