Football is strewn down the years with cases of managers who "made a difference". Right now the classic case in Britain is Brendan Rodgers at Liverpool, a leader who has transformed an ailing giant by the sheer application and skill of his methods.
In this context, these days are becoming a growing nightmare for Ally McCoist at Rangers. In response to the question, "does McCoist inspire Rangers, does he rouse a team to a performance?" growing numbers of Ibrox fans are either wincing or simply looking the other way.
Sunday's Ramsdens Cup final at Easter Road between Rangers and Raith Rovers wasn't just an atrocious football match in its own right - that bit was bad enough. For McCoist observers, it became one more damning piece of evidence, as Raith saw off their plodding, dysfunctional opponents.
McCoist was a Rangers legend as a player - but just what is it that he is lacking as a manager? His players' laboured performances on a football pitch repeatedly speak of poor leadership, poor management, poor coaching. Can there be any other way of looking at it?
In recent days a discerning section among the Rangers faithful, otherwise desperate to go the extra mile for McCoist, have turned against him. It has left this 51-year-old Ibrox legend facing his worst crisis in his near 30-year association with the club.
Those Rangers fans who cannot bear to call out McCoist for his lack of management skills gamely try to shift the blame elsewhere. I mean, look how poor the players are, they say. Or, look at the political turmoil surrounding the club…how could any football manager thrive in such an environment?
There are grains of truth in all these McCoist get-outs. Goodness knows Rangers are a financial, political and social shambles. The club lurches from anger to anxiety to uncertainty in ways which must make many supporters despair.
None of this, though, can shift the focus away from McCoist, and his apparent lack of effectiveness in his job.
Right now the accumulated evidence suggests he is a sub-standard Rangers manager. It suggests that motivating a team is beyond his powers on a consistent basis. McCoist appears to lack that much-lauded, if mercurial, quality called "presence": that gift whereby players and teams elevate themselves via their manager.
In short, Rangers under McCoist cannot better themselves on the pitch. His team, despite being strewn with tried-and-tested former SPL yeomen, appears to have gone backwards, not forwards, on his watch. For many, it has all made for a painful vigil.
Following on from the abysmal straining by McCoist's players to beat Raith on Sunday comes this Saturday's Scottish Cup semi-final against Dundee United at Ibrox. It is a game from which McCoist desperately needs to claim a result.
Despite all the gruesome evidence to the contrary, he might have a chance of just so doing. Dundee United are superior to Rangers in terms of skill, and have recent Scottish Cup success between these two teams on their side, but this will be Rangers, at Ibrox, and with a large home crowd urging them on.
It represents a critical juncture for McCoist. He has a golden opportunity to lead Rangers to a Scottish Cup final, in the face of mounting levels of criticism and, in some cases, abuse. The game cannot be overstated in its importance to him.
Rangers have a host of players - Cammy Bell, Lee McCulloch, Ian Black, Lee Wallace, Nicky Law, Jon Daly, Dean Shiels and others - who are reputedly steeped in top-flight experience. They cannot be this bad, can they?
It remains the case that any highlighting of McCoist's alleged failings is a painful business. He has brought a huge appeal to Scottish football over the years, not just with his goals in a previous life, but with his personality and charm on various levels. Few, in truth, have not warmed to and admired McCoist, this writer included.
McCoist knows, however, that football is unabashed and pointed in its opinions. That's how the game is and how it should remain. And, in this context, he is having a very hard time of it.