I've been at it long enough (several decades) I don't do simulated swing trading anymore. Everything is live. But I have moved up to an "Investor" now. Easier on the taxes too. All LTCG, qualified Dividends, etc. (My main trading account is after-tax $$'s, low 7-figure)
Are your simulated trades entering into collapsing technical areas, like breakouts and breakdowns? If so, markets move fast and liquidity is thin in those areas, so you have to factor in more slippage. If your simulated trades enter into where price is basing, then you can factor in less slippage.
%% THAT\ + your guts or anyone's guts knows the difference in pretend [paper] profits + real money. [2] Adding 2 the complexity, patterns repeat but seldom repeat exactly.......... [7.77] Even worse on small time frames , data differs more; but doing huge volume, IP co does OK with paper trades , sub % sector, sadly. Useful sometimes by stopping a bad entry+ paper notebook helps.
%% Good points, good %. 1 ] And have a lot of uses for paper=trading notebook, paper charts........ 2] I did not know the metals dealer clock-time stamp was few minutes faster than my auto clock; not a big deal . But no wonder, he had locked the main door ,my sell was time stamped, ''4:01 '' '' Actually they close @ 4, but he loves his work, no problem . 7.77] Good paper record; the weakest ink+ paper is better than the strongest memory
I've used IB paper trading for a few years and it's good but not perfect. It can't handle high volume or high volatility or thinly traded stocks. It does seem to insert paper orders into a queue so orders get filled at the appropriate time. In high volume an order can be submitted but it isn't acknowledged (and hence not in the queue) for a long time. That happens less with live trading. In high volatility or thinly traded the price can move past your order and not get filled. With low volume your real order may move the market and that won't happen with paper trading.
%% AMAZING; the difference in computer-internet prices \ + real time dealer$, even with metals,, copper....................................... Even more so when 30 miles away from each other