Rolling Dice like a DM

So, I’ve found that when I DM, I tend to roll really poorly.

Now, I’m not the type of DM who is in competition with players, so this doesn’t bother me. However, it’s a bit disconcerting when more than three-quarters of the time, I”m simply rolling under 5.

When you’ve got a massive white dragon who’s unable to impale a single hero on his claw, or when the heroes have more than a dozen archers fire at them and miss every time, it gets to you.

I know it’s not my dice, because when I use them as a player, they roll just fine. It’s just my DMing, it appears.

Do any of you have this issue? Do you help your players (accidentally) when you DM through bad rolling?