Not certainly; there are some scenarios which you wouldn't be able to plan. These scenarios usually knock only once and happen in very short time; it can be considered as jockpot for a trader. A plan is just a guide, thus it won't decide your winnings.
but still it can reduce the risk compared to trading without a plan. we know that before trading, gathering useful information is very necessary, and making restrictions so that we avoid the risk of loss. when you don't make a plan, of course you will only hold back and wait for the price to return to normal, when the price has fallen.
A trading plan is a simple data that is recorded by observation and from the respective growth of the asset. Here the same pattern of growth won't happen when we get into buying or selling, we just move on some calculated predictions. This prediction needs to coincide with real growth. This won't happen every time as planned for every trader. By this time some experience loss and this can be eliminated with the help of trading plans.