When to take profits and losses

Tasty trade Options Jive on 2-5-2016 did some research (Slides) on when to take profits and losses by giving a quick rule of thumb whether you're taking profits at 25%, 50%, or 75% and when you should get out to allow you to have the winning percentages.

The chart below provides the quick cheatsheet. Note, if you sold a strangle for $1, exit trade for $3)
Source: TastyTrade

Our studies have convinced us to manage winners at 50% of max profit, and other studies point to managing losses when the loss is equal to 2x the initial credit. With this management style, 80% of our trades must be winners if our average win is 50% of the credit received, and our average loss is 2x the initial credit received.

What happens if winners are managed at different percentages of max profit? How does this change our required win rate to break even? Can losers still be managed at 2x the initial credit, or does that have to change as well?

The relationship is simple: the sooner we plan on taking profits, the sooner we need to take losses in order to keep our required win rates "realistic." For example, if we manage winners at 50% of max profit and manage losers when the loss is equal to 2x the initial credit received, we need an 80% win rate to break even. If we instead manage winners at 25% while still managing losers when the loss equals 2x the credit received, our win rate needed to break even jumps to 89%.