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.
in the beginning, start always with Brawler's Gloves(punch)that is on the tab attack dmg and then critical stike (i think), 1 healing potion and 1 mana potion and try to make items with critical chance. The items slots are 6 so try to make avarice up to 4 slots then 1 slot for zeal and the last slot take bf sword and make it infinity edge.then try to transform zeal to phantom dancer and then as it goes on sel and buy as an ex. after phantom dancer, sell the 1 avarice buy bf trasform it too bloodthirster..but if you dont have gold to buy new items keep the avarice until to get something expensive as the bf dont waste avarice to get something as lifesteal scepter its pointless.after the 3 avarice you are going to start seeing more often criticals up to 250-300 without having any dmg only with runes and avarice..after you complete and the infinity your dmg its should be around 500-550 almost constant cause you are going to have around 75% critical chance.
summoner splells:u might say that im noob on using heal but trust me its not at all i give a lot of importance on heal thats why i build that way the skill sequence.heal can help you in the beginning when u run out of mana in battles, for avoiding 1st blood(since that gp is a slow char in the beginning). exhaust is for some players like trynda (my other main char)in a combination with passive of gp you can kill him easily just hit him and in the endless rage exhaust him and continue hitting him, or like yi with his ulti so exhaust i use it more for defense.
critical: with runes you are going to have extra 46% critical dmg and with masteries, in total 56%crit dmg thats a lot trust me XD
advice:as a player with around 750wins and around 300 are with gangplank i advice u to be patient with this char in the start and you will see results dont be agresseve but annoying hit and back, hit and back all the time..and remember to keep your critical chance more than 65-70% so to be able to say GP IS AN OVERPOWERED CHAR! YAAAAR! thank you all for reading all this have fun!