Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Jax is the ultimate melee champion IF you can play him right. He can only be played good or bad, not something in between. This is my suggestion to play him good. Let me mention my best score with this build: 27-0-19 in 5 v 5. I played with totally noobs and frail champions. Jax needs dodge to survive. He needs to get his counter strike going all the time cuz his leap strike have a pretty long CD so he have to get close to them as much as possible. Thats why i have chosen exhaust and ignite as summoner spells. Exhaust slows and blind the target so he can move close to it fast and if the target has got low life he can use ignite if it runs out of range or to a tower.