Those numbers are deceiving to say the least. Some of them come out of a full run on tires and fuel and others just go out and run a much smaller segment. In that final practice only 19 drivers of the 41 that practiced ran 10 or more consecutive laps. Using your Gordon example, he ran at least those 29 laps on one set of tires on the same setup. It doesn't tell you how many laps he continued after his 29th lap although he did run 34 total laps in that final practice. Without all of the drivers making full runs though it's really hard to get any good info out of it IMO.