Slim your right to question this as it can be over complicated.
The Old Man explained it the best but I will simplify it even more. Its simply a dog lifting his head and running the scent in the air in a more direct line. It can be faster because if that hogs been weaving a little or meandering around instead of following every little weave in and out, it will just run a straight line through it making up ground on the hog. Your dogs probably do it and you just didn't know that is what people call it, as most stock bred cur dogs drift, some more than others. That is the main way winding type dogs run a track from what I have seen. Now how much a dog will drift is a different story, some get real good and start what us cat and fox hunters call cheating, in which they will "swing" and "drift" a track a lot more, sometimes more than the scent will allow. This is a double edge sword, because if the dog is really good at knowing how the game runs he will catch a lot of game a lot quicker, but if he is not this is where dogs make big losses and can end races. You can really see this cat or fox hunting big packs of dogs on the Garmin due to the way cat and foxes run. This is why a lot of these houndsmen like to have both in their pack and when the dogs have run together enough the cheaters will even learn that when they lose the track that they can go back to the voice of a certain dog they trust (track straddler) and get back on the track and try to get back in the race though sometimes they are too far behind.
Also if the hogs you are running are just running straight lines then drifting or track straddling doesn't make as much difference, whats makes the bigger difference in this case is running heads up or nose down. Just some observations I have made.
This makes a little sense now. You say cheating a track and I’m picking up what your putting down because my uncle talks a lot lately about how my sketch gyp cheats hogs or tracks. She’s starting to do it more often. At first it resulted in a lot of lost tracks, she is getting better at staying In them as she gets older, coming 3 year old this summer. Because of the way our hogs seem to run, it is very rare to see a hog cross, we don’t hunt big blocks with cut overs and such. The other night in the corn fields was the first time in a long time I got to see a hog cross out front of my dogs she was 80 yards behind or so when she broke out but pretty much right where he was. Probably has a lot to do with grain your gonna have to get in the same turn row you push him. She was stretched out and and pouring it to him when she hit the scrub flat he went in to and had him put up in a tank within 300 yards. Guess I’ve just never heard it called anything because it’s just something these dogs I’m around have always done
Doesn't surprise me your gyp will both cheat and drift a track. Like was said before most winding type dogs like curs will drift a track. As for cheating that doesn't surprise me that she does that either with her being stock bred. One will lead to the other quite a bit with intelligent dogs.
For me its tough to tell hog hunting if our dogs ever cheat because our dogs are silent and the kind of country we run we don't get to see the hogs until they are caught, but cat and fox hunting is a different story, its really easy to tell when you have a whole pack of dogs all running the same piece of game for a good amount of time. You can look at the garmin after the race and see who likes to do what.