Recently sacked Manchester United manager Jose Mourinho and incumbent Manchester City manager Pep Guardiola coached winning teams across three major European leagues.
While Guardiola has consistently improved or helped his teams play at high levels (expressed as Elo ratings , which rank football teams based on relative performance), Mourinho was much better in his earlier stints than his later sojourn in England.
In the below visualisations, green denotes peak Elo rating achieved, while red denotes the worst. The blue lines represent Guardiola's record, while the orange represents Mourinho's.
(With inputs from Srinivasan Ramani)