Originally Posted by Tennishacker
Is it legit, yes, but IMO not within the, "spirit of sportsmanship".
Sounds like your ability to control your serve places you in the 4-4.5 range, your opponent seems to be a lower rated player.
Your strategy will work against lower rated players, but will not work with 4.0 and higher rated players.
When I play matches (match pressure), I always try to play my best, always looking for ways to improve my game.
For many people, "trying to play their best" means playing beyond their limits and losing. It feels great to hit hard with the idea that it will help improve your game. The reality is that this is why many people lose.
There is no shame in hitting a 50% serve that is more effective than your normal serve.