Imagine you are a professional pitcher and you only have the ability to throw one pitch. It's a fastball with good movement that's decently fast. Definitely not the fastest. Perhaps maybe a little above average speed, but nothing special.
How could you be a great pitcher? It can't be about focusing on the lack of pitch repertoire – that choice is gone in this hypothetical scenario.
It would have to be about perfecting everything else. The accuracy of the pitches. The slight variances in speed to keep batters on their toes. The timing of the wind up. The pressure you put on runners with your pick-off move.
Having accuracy does seem to do wonders for a baseball pitcher. Take for example Koji Uehara. He was a 38-year old pitcher in 2013 when he earned the MVP title in the ALCS (American League Championship Series.) He didn't have the fastest pitches (in fact, pretty slow fast ball at sub 90) or the most diverse pitching repertoire. What he had was accuracy. He threw an unbelievable amount of strikes relative to balls. And the outcomes show the effectiveness of such skills (They won the world series that year.)
There's something to be said about being a one-pitch type of person. Being really good at delivering on that one thing. You end up becoming known for being good at that one thing. And because you're good at it, you earn the trust and respect of others.
With minimized distractions and clarity on what to focus on, the one-pitch becomes the perfect backdrop to be able to let the other stuff that matters shine through.
Are you focusing on too many things?
Maybe it's time to reduce the pitching repertoire and focus on the effectiveness of the pitches instead.