Question regarding Quarterly estimated taxes (yes, I do pay them)

[LondonBroil]

I was told this year that estimated tax payments have to be equal amounts. So back in April, I decided what I'd probably owe for the year, divided it by 4, and made my first payment.

Well, since I suck at poker, I must have run REALLY lucky this year and so far have made a little under twice what I thought I was going to.

Can I make my last estimated payment (due 1/15) larger than my other 3 or will I just have to pay penalties come 4/15? If I CAN make my last payment larger, couldn't I have just paid something small like $50 for the first 3 payments then $6000 for my final one?