Segwit activation signaling is now at 45%. Total hashpower is at abot 5 million TH/s. One avalon miner got 7,3 TH/s. Lets say 2,5 million / 7,3 = 340000. This gives me a chane of 1/340k every 10min.
So its 1/2.6k each day. Yes seems low.

Please verify my calculation.

I will flag also this question.