validation check to prevent people from opening duplicate deals

we have some reps for some reason going in an opening duplicate deals . . . this is obviously a big problem since it double counts those deal amounts

Now-- i could create a list and surface it to the team--although I would love to make this impossible from the start.

It there were a rule that I could set up to inform them before they add the deal there is already one open in that pipeline that would be phenomenal!

+1