I have tried several different ways of tracking my play. First 'time', because all the books talk about such and such rounds per hour and EV in terms of hour. Once I decided that I didn't want to play all the negative counts, opting for not playing a TC of -3 over playing with minimum bet and negative count index plays, my sessions became much shorter due to aggressive wong outs. So I ended up with all these small segments of time. 12 minutes here, 17 minutes there, 8 minutes over there. It just didn't make sense to be adding these up and trying to stack them into hourly increments.
Next, because I was playing Atlantic City and all shoe games, I went to tracking number of shoes played. But the aggressive wong outs created the same problem....partial shoes.
Plus there was the added problem that all shoes are not created equal. If I was fortunate enough to get a game heads up or even with one other player, the rounds played in that shoe could vary as much as 45 -50 (heads up) to 12 or so for a full table. It just didn't make sense to count each of these segments as a "shoe played".
In the end it really comes down to rounds played. Your results and expectation will come down to rounds played, so that seemed like the thing to track. Obviously I am not going to sit there and count rounds along with my primary count. So I use estimation. I use 2.8 cards average per player per round, including dealer, unless it is heads up play in which the dealer drops to 2.7 for a total of 5.5 (player and dealer per round).
I then just add up all my rounds played to figure EV and win rate (per 100 rounds). This way 50 rounds played is 50 rounds played, whether I get those 50 rounds playing 10 minutes in a heads up game or over an hour playing in the shadows on a crowed weekend night.
Rounds is what matters. And it is rounds
played, not rounds seen. Rounds played is going to determine both EV and actual win (in the longrun).