in the local Crit for my (Cat D lowest Cat locally so Cat 5) I took 2nd and my teammate took 1st

I'm a strong rider generally than they are and on most rides I will pull the majority of the time and then once we begin to climb they're dropped off the back and will usually catch up on the flats.

the crit was mostly flat some slightly elevation but nothing that you could call a climb.... an arguable false flat

they had my number that day and it's great for them but I'm still not sure what it is that allows me to drop them on climbs but not keep that gap

how do I improve my flat riding so I can at least hold any gaps I create on a climb and ideally open them further ?

I'm not looking to completely shell my teammate but I don't like that this happens with other racers as well