Why a daily target halves the result
Many traders want the same thing from a system: a steady 200 $ a day with a Micro contract, and no long runs. The simulator answers both wishes with numbers.
A fixed 200 $ profit target per trade halves the annual result, because the system's profit comes from the few trades that run to the next liquidity level, often 300 to 600 $ on one Micro. Capping those at 200 $ keeps all the losers and cuts the winners.
'Stop trading after 200 $ for the day' changes almost nothing: only 24 % of trading days reach 200 $ with one Micro at all, and the average day makes 31 $. The rule rarely triggers, and when it does it removes a second winner.
A time limit is a different kind of cut. Closing a trade that is still below its entry after sixty minutes removes trades that were going nowhere; it keeps the runners, because a runner is above its entry by then. Result: nearly the same profit, drawdown down from 916 $ to around 800 $ in version 2 and to 573 $ in version 3, longest losing streak from ten to eight.
Trailing the stop tightly and adding contracts on a good run were also tested: both worsen the ratio. Scaling works only by fixed size, two Micros from about 3 000 $ of account.
The lesson generalises: cut by time what is not working, not by amount what is. The amount you would cut is the amount the system lives on.