I am curious to know how many times maximum breaks were scored in a decider frame. I remember one from Ronnie but don't remember the opponent.
Were there any more records like this?
This information can be obtained from the maximum break page on Wikipedia. The section "match-winning maximum breaks" lists 18 breaks in total and 5 of them are in deciding frames.
Here are the 147s made in deciding frames:
- Stephen Hendry - 1997 Charity Challenge, Final
- Ronnie O'Sullivan - 2007 UK Championship, Semi-final
- Mark Davis - 2017 Championship League, Group final
- Mark Davis - 2017 Championship League, Winners' Group
- Martin Gould - 2018 Championship League, Group 6
In the Championship League, almost 200 matches are played and each match is won by the best of 5 frames. Therefore it is very probable to see a 147 in a deciding frame.
We should also note that Ronnie O'Sullivan is the only player who has such a break in a ranking tournament. On top of that it's a UK semi-final.