When it comes to Tug A Truck, it is a battle of not only horsepower, but traction and driver skill. There is a lot more to being competitive then just hooking up and mashing the throttle.
Most organizations will segment the trucks into weight classes to put everyone on a more level playing field. But even then, not all tires have the same amount of traction. It is, also, pretty common to see a driver light up his tires and smoke them pretty good, before the hook is done. They are doing this to put some heat into the tires. Some tires will become more pliable when warm and that will give the tires more traction.
In addition to traction, there is a huge game at the line that drivers play. Some drivers start to put a huge load on the other truck. This lets both trucks start out with their suspensions already loaded, transmission, axles and the rest of the running gear already engaged and the engine under some load to build some boost. On the other side of that, there are a number of drivers that don’t want to start that way and will allow their trucks to roll backwards before the pull has started. This is a false start by the competitor trying to put a load on the truck. Depending on the organization, this may only be tolerated one or two times before you lose that hook. While this is more of an automatic vs manual strategy, there are some games that can cause people to get behind at the starting line.
The video above shows what happens with the driver in the yellow tractor has too much traction and instead of the tractor sliding backwards it is actually lifting the front end up and eventually rolls over.