thumb|upright=1.25|[[Ronnie O'Sullivan has made a record 17 maximum breaks in professional competition.]]
A maximum break (also known as a maximum, a 147 or, orally, a onefourseven) is the highest possible in snooker in normal circumstances and is a special type of . A player compiles a maximum break by potting all 15 with 15 for 120 points, followed by all six for a further 27 points. Compiling a maximum break is regarded as a highly significant achievement in the game of snooker and may be compared to a ninedart finish in darts, a holeinone in golf or a 300 game in tenpin bowling. A break of up to 155 is possible if the referee awards a before any of the reds have been potted, but breaks exceeding 147 are exceptionally rare, having occurred only twice in professional competition. Any break greater than 147 but not 155 is not considered to be a maximum.