Throwing a hook (or curveball, or any of the many other terms people use to describe a shot that doesn't travel straight down the lane) is a method of bowling proven to be effective. You see pros do it, league bowlers do it and recreational bowlers do it. There's a reason all these people throw hooks: it works. Bowlers who create an entry angle close to 90 degrees (meaning the ball enters the pocket perpendicular to the 1 and 3 pins for righties or 1 and 2 pins for lefties) throw a lot more strikes than bowlers who don't.
However, that doesn't necessarily mean anyone who throws a hook will be better than anyone who doesn't. Consistently hitting the pocket on a 90-degree angle is far from simple, and a bowler needs to be able to control the hook rather than merely hook the ball.
The Perception: "He Throws a Hook. He's Good."
Many people have seen this, maybe with a co-worker at an office bowling party or even a stranger during open bowling. Let's use the office party as an example. Typically, most people at such a gathering won't be die-hard bowlers, but if one of your co-workers steps up and throws a hook, people are impressed. They immediately assume he's a good bowler, based solely on the revolutions he put on the ball. Never mind if he misses badly and leaves six pins standing - the mere fact the ball curved gives off the perception of being a good bowler.
So, if you want to get better at bowling, is it as simple as starting to throw a hook? Sort of. That is, you should learn to throw a hook, control the hook, know how to throw big hooks, small hooks and no hooks, and, generally, learn how to bowl. Just because someone knows how to curve the ball does not necessarily mean that person is a good bowler. Putting spin on the ball may be the only skill that person has.
Is a Bigger Hook Better?
Watch any pro tournament. There will be four or five guys in the finals on the TV show, and they will all have different bowling styles. Some will throw huge hooks, others will have moderate hooks, and some others might even throw the ball almost straight. Each one of the pros bowls based on his or her own strengths and weaknesses. A hook that encompasses the whole lane works better for Bill O'Neill than it does for Chris Barnes, and vice versa, but that doesn't mean Barnes can't add hook when he needs to or O'Neill can't take some off when he needs to. It's not the magnitude of the hook, but rather the versatility of pro bowlers to know how and when to use the spin on the ball that makes them the best in the world.
The Facts: Versatility Makes Someone a Great Bowler
The perception of someone who throws a hook being a better bowler than someone who doesn't isn't likely to go away, and, in many cases, is true. But if you really want to improve your game, it takes a lot more than simply throwing a hook. Learning to do so is an important first step, but after that, you need to consider how you can adjust that hook to the lane conditions, specific spare leaves and even your opponents.
Learning to throw a hook is great. But it's far from all there is to know about bowling.