If you're using a created golfer to try and win an open event, make sure you have all of your best equipment selected. These new clubs and gear can make a huge different in your stats under the hood, so it's worth checking out all of your new gear as you unlock it.
You'll gain new clubs and gear as you make your way through the career mode, and the game helpfully points out which stuff you've unlocked while showing you what stat impact it will have. There will be a bit of variance in some clubs, as a higher-level driver might actually provide more spin but at the expense of power. The grips you unlock are just cosmetic, but the club shaft modifiers provide additional club power of varying degrees. The sponsored golf balls available will also provide varying amounts of spin and power on your shots.
For EA Season Ticket holders, you'll have access to a set of gear specific to that purchase, and you'll be able to gain significant stat boosts across all of your clubs. In fact, those clubs are better than almost any other equipment in the game, save for the very high-level stuff.
How much do you upgrade your golfers via their eqiupment?