强中自有强中手 [- - zì yǒu qiánɡ zhōnɡ shǒu]However strong you are, there's always someone stronger.; Among the stronger there is always a stronger.; catch a tartar; diamond cut diamond:
•¶强中自有强中手， 能人背后有能人。 However strong you are, there's always someone stronger.; For every able person there is always one still abler.