Digging holes two feet deep is hard work. There will be roots and stones. It is especially difficult if there is an old piece of concrete in the ground for an old wooden pole that has rotted, and professionals leave it and dig new holes between the old pieces to avoid this work. Fences erected by builders are particularly prone to having large chunks of concrete, but they are often too superficial.
This is so difficult that I decided not to use wooden poles again, only concrete. The wooden posts rot and spikes come off at ground level, where the moisture and air content is optimal. A concrete pole is very heavy, although two sturdy people can handle it. The same goes for concrete gravel boards, which I also recommend for the same reason. It's good to leave a space for hedgehogs, perhaps at the end of the race, or to leave out one of the dirt boards.
You can get a special alcohol level accessory that attaches to the pole. If you are a beginner, place the first one, place it perfectly upright, cover it with pieces of brick or concrete while you mix it with a shovel, make sure it stays perfectly upright and that nothing happens to move it for at least a day. To avoid seeing a large expanse of lumpy concrete above the ground, you can make a simple box with shutters around the base of the post at ground level so that the top few inches are small and tidy. Then you can dig the next hole and, when you have done it, you have taken out the pole and taken a break to drink tea, the concrete in the first hole will have hardened, although it will not have strength, so you can wait until the next day before placing the gravel board and the fence panel and placing the next post against them (not so tight as not to be able to put a new one in from above when necessary).
If you're an amateur, I'll be happy to make just one post a day so you can be sure that you won't let go of the old post on its concrete before it has time to harden. Otherwise, do it fast enough so that the concrete is still flowing and you can re-tamp it if it moves. On a windy day, the panels will rock the posts and release them until soft concrete is formed. If you're working fast, you need each hole ready before you start placing the previous post.
This will require about three people. A straight-sided hole the shape and width of a bucket is better than a large, wide crater.
