Many players are much stronger on one side than the other. Often this is the forehand, but not always. They generally find tactical ways through serve, receive, and placement to cover for their weaker side while trying to dominate with their stronger side. This often works, to a point. However, it means accepting an inherent weakness in one’s game, which often becomes a barrier to improvement.
Slightly stronger players – the ones you are trying to learn to compete with – will usually have the tools and tactical skills to play into this weakness. For example, if you have a strong forehand but weaker backhand, a smart opponent will simply serve fast and deep to the backhand, and hit fast, quick rally shots there, with the threat of a fast serve or shot to the forehand if you try to cover the backhand with the forehand. Or he might serve short to the forehand, drawing you in over the table, and then go deep to the backhand. Or he might just serve deep to the forehand and quick-block your return to the backhand. There are many ways of finding the weak side.
Supposed you are stronger on one side. Much of this might be because of your grip, playing stance, or just your mental mode, where you focus on the strong side (for example, are stuck in “forehand mode”), and so get caught on the weak side. But these are relatively easy things to fix, if you know what you are doing. (If you don’t, get a coach or consult with a knowledgeable player.) Spend some time developing that “weaker” side so that when you are forced to use it, it’s pretty strong, even if not as good as your stronger side. It might be as simple as learning to mentally change from “forehand mode” to “two-winged mode,” or even “backhand mode.” Or it might mean small changes in your grip or stance.
What you want to do is to dominate many points with your strong side when you can, but also force your opponent to sacrifice his own normal tactics, forcing him to instead use his tactics to find your “weaker” side. To do so he’ll have to adjust his tactics and game, which puts him at a disadvantage until he actually gets to the weaker side, which essentially means he’s willing to give up points in return for doing so. And then, when he finds it, you want him to find that weak side isn’t so weak, and that even after giving up points to get to it, he still has a difficult struggle to score.
And so he’ll be stuck trying to decide whether it’s worth giving up points to find your “weak” side, which isn’t so weak, or give up on the tactics that avoided your “strong” side – and so you’ll be able to play your strong side more often. It gives him a no-win tactical choice. Isn’t that a wonderful thing?