Why do managers struggle after stepping up to 'big-six' clubs?

Image source, Getty Images Image caption, Former Bournemouth boss Andoni Iraola (left) is set to join Liverpool, while Thomas Frank moved to Tottenham from Brentford By Prudent Nsengiyumva BBC Sport journalist Published 58 minutes ago Moving from a successful Premier League side to a so-called 'big-six' club is sometimes seen as the natural next step for a manager. By the 'big six' we are referring to Arsenal , Chelsea , Liverpool , Manchester City , Manchester United and Tottenham . We do not use that term to disparage the likes of Aston Villa or Newcastle who have qualified for the Champions League in recent seasons, or indeed any other top-flight team. But those six clubs have largely dominated the top of the table over the past 15 years or so. So will Andoni Iraola, who has reached a verbal agreement with Liverpool , be able to make the step up from Bournemouth after finishing, ironically, in sixth place with the Cherries? The data suggests it is one of the toughest transitions in the game - with short tenures, mixed results and no major silverware won by a manager taking that step within the Premier League. In recent seasons, Thomas Frank, Graham Potter and Nuno Espirito Santo all struggled to make the leap. Iraola will make Liverpool fans excited again - Murphy Published 42 minutes ago A series of short spells For managers who earn a move to one of the Premier League's biggest clubs, the opportunity can arrive quickly. So too can the scrutiny. The most consistent pattern is how short those spells tend to be. Of the managers BBC Sport has analysed, the majority failed to last two full seasons, with several dismissed before completing their first campaign. David Moyes' appointment at Manchester United in 2013 remains one of the clearest examples. Hand-picked from Everton by Sir Alex Ferguson - who urged supporters to "stand by your new manager" in his farewell speech - Moyes arrived with both backing and expectation. He was dismissed just 10 months into a six-year contract. The Red Devils missed out on Champions League qualification for the first time since 1995. Roy Hodgson's move to Liverpool followed a different path but ended similarly. Appointed in July 2010 after leading Fulham to the Europa League final, Hodgson said he was honoured to be taking "the biggest job in club football". But he was gone by January the following year - with the Reds 12th in the league having won just seven of their 20 matches. Other managers followed a similar trajectory. Potter lasted 22 league matches at Chelsea after joining from Brighton , while Nuno managed just 10 at Tottenham after taking Wolves from the Championship to a Europa League quarter-final. More recently, Thomas Frank's time at Tottenham reinforced the same trend, with the Dane joining Spurs after an impressive spell at Brentford but only lasting 26 games. Even when managers have been afforded more time, success and stability proved elusive. Mark Hughes spent about 18 months at Manchester City