Nice to see someone that actually sizes their trades sensibly - 1 ES contract per $100k.
Nearly every novice maxes out their leverage, that is why most go extinct inside of a few months. I always cringe when I see these all to common comments that go like "I just opened my xxx account with $10,000. I am new to trading and put on a real small position with 5 CL (oil) contracts." That trader is on the fast track to the road of ruin.
Honestly, this is just a matter of how the trader plans to trade. If a trader is day trading, and lets say uses 3 point stops, this would be a $150 stop per trade. On a 10k account, with lets say day trading margin at 1k, this would be he has 9k to lose before he can't trade. If he sticks to his stop, this would mean that he can be stopped out 60 times in a row before reaching the 9k drawdown. Regardless of what his plan is, whether its a 1:1 ratio, so profit target is also 3 points with a win rate of over 50%, or 1:2 ratio, so 6 point target, thereby needing to only 33% of his trades to be profitable, he will still have some winners in there, which should extend his ability to place more than 60 trades.
My point is that with 10k, he can put on dozens and dozens of trades, and if he has an edge, I don't imagine he will get anywhere close to his max drawdown that blows out his account.
Now things of course work out differently if you are swing trading. Your stop might not be 3 points, but 10 or 20 points, and hence $500 or $1000. In this case, you only have to be wrong about 9 times before you have no more money, but you would hope that there would be some winners in here as well, and these winners would hopefully be more profits than the losers.
Now the OP says he doesn't use stops, so who knows how this all works. Its very easy to imagine being in a long, then down 20 points, switching to short, just as the market now goes up, and then down another 20 points. In this case, he could already be down 2k, but based on what the OP has said, I doubt he will be selling every bottom and buying every top.
Anyway, my point is that 10k is actually plenty to trade 1 ES contract.