As Andre Villas-Boas is about to discover, hell hath no fury like the managerial merry-go-round Its momentum is provided by the energy generated by lost dressing rooms, senior player revolts and Frank Lampard getting a mard on for having to sit on the bench. The exact location of the merry-go-round is unclear. Rafa Benítez is on it at the moment and Pep Guardiola is expected to flirt with the idea of having a ride later this year before signing an improved contract at Barcelona, so it must span the continent. Out-of-work managers can stay on the merry-go-round for long periods, forced to survive on a diet of rumoured shortlists and candyfloss, but surely the likes of Joe Kinnear are eventually politely asked to get off and have a go on the managerial big wheel, or the notoriously adversarial managerial dodgems. The accepted signal for managers wanting to get off the merry-go-round is to throw their hat into the ring. This is trickier than it sounds. The rings in question are made to look deceptively larger than they actually are in order to entice riders to recklessly chuck their hard-earned headwear away. As well as inviting such fearless and wholly worthwhile extension, the merry-go-round metaphor serves to remind us of an important skill for carving out a managerial career. Aside from the usual attributes that good managers are praised for - tactics, team selection, graceful technical area navigation, shouting - from a long-term point of view there's little as important as judging when to jump off or board the merry-go-round. Mark Hughes has been guilty of misjudgments twice in the last 12 months. He resigned as Fulham manager seemingly expecting to take the reins at Aston Villa, only to take the rather more disappointing reins of a wooden horse when it became clear that Randy Lerner fancied inciting riots in Birmingham by opting for Alex McLeish. Hughes will also be kicking himself now that the Chelsea job is available. His reasonably impressive spell at the helm of Manchester City would have put him in with a decent chance of taking over at Stamford Bridge, at least in the short term. Instead he's stuck with Queens Park Rangers and facing likely relegation to the Championship. By contrast Roy Hodgson is a merry-go-round expert, with only his understandable desire to have a crack at Liverpool standing out as folly in a ridiculously long club-hopping career. Steve McClaren seems to be something of a latter-day Hodgson, seamlessly escaping a horrible mess partly of his own creation at Nottingham Forest and re-entering the welcoming arms of FC Twente, with whom he is contesting the Dutch Eredivisie title. By contrast some managers stay on the merry-go-round for far longer than recommended. Will once-bright young things such as Alan Curbishley, Glenn Hoddle, or Paul Ince ever disembark and be offered an enticing job again? Does a similarly dispiriting fate await Villas-Boas? Out of work, fading from memory, doomed to spend eternity travelling round and round in an endless circle with Mick McCarthy and Dave Bassett for company. Probably not, no. He'll take the Porto job again, prove how capable he is, and forget that this whole sorry eight months ever happened.