When you think about what is required to be a good runner things like persistence, passion, the right genetics, and consistent, quality training come to mind. Undoubtedly all of these things are invaluable.
I work with a ton of PASSIONATE runners who live and breathe the act of running. Constantly in pursuit of the next goal, the next challenge, and the next personal best they sometimes push themselves to the brink and beyond.
While I preach the virtues of quality, consistent training over time as a way to maintain a high level of health and running performance, the reality is that you cannot train/race at a high level ALL THE TIME!
Simply look at the best runners on the planet. Does Kara Goucher run 10-12 races all out every year? Do Ryan Hall or Meb Keflezghi push themselves to the limit a dozen times/year? Unequivocally, the answer is NO.
What you see with Kara, Ryan, and Meb is a few peaks/valleys during a given year of training. They may target a handful of events per year. Meb won the New York Marathon last fall and didn't run another Marathon until Boston in April of this year.
This is not to say that Meb is sitting on the couch eating potato chips between races. Quite the contrary. But, Meb undoubtedly dialed things back a bit after winning the NY Marathon and then GRADUALLY ramped his training back up in preparation for Boston.
Meb trains year round and for many people this is absolutely a reality as well. But, training hard all the time and attempting personal bests at more than a handful of races per year is almost inevitably a recipe for burnout and injury.
This is not to say you shouldn't participate in 4 or more races per year, but if you are looking to have 'peak peformances' at '4' key races per year, every other race you run in should be treated a bit more casually. Pulling off a peak performance takes time, patience, and the proper alignment of the stars.
Most of us will never compete at the highest level, but there's a reason why the pro's are 'professionals'. One of the big reasons is they know how to train properly. They know how to train to keep themselves in optimal shape while steering clear of aggravations/injuries.
If your longterm goal is to become the best possible runner you can be, emulate the approach many of the professionals employ. You'll more than likely find yourself peaking for the events that are important to you, steering clear of significant aggravtions/injuries, and become a better runner in the long haul.