Saul does alright. He rules over Israel for forty-two years, which is record breaking. 1 Sam 13:1. He wins victories against the Philistines. But so does his boy, Jonathan. See, e.g. 1 Sam 14:1-14.
The Bible talks a lot about armies being confused and killing each other. It is a major component in Saul’s big victory over the armies of the Philistines. 1 Sam 14:14-23.
Here’s something interesting, Saul makes a dumb vow about no one eating. His boy is off killing Philistines and doesn’t hear it, so he eats too soon. AND Saul does not kill him. And the reason he doesn’t kill him is the soldiers are like, “Hey, c’mon, he saved us from all those dirty Philistines.” Seems like a big deal, but recall, Saul also didn’t kill the dudes who were talking shit about him when he took over as king. Saul also tries to do a sacrifice, himself. That makes Samuel pretty upset.
He’s tall and good looking. He’s from humble roots. He’s a hot head that gets Israel into unending war. He doesn’t really care about the rules.