Indeed. Like that season under him when we won 21 of those 38 games?
Good managers rely on having good players...technically proficient and professional in outlook. Eventually, after 18 months in the job, even Roberto couldn't get a consistent tune out of the dressing room clique.
Yeah luck of the draw does play a big part and can hugely influence a managers cup record, thus making it a lot harder to actually judge whether a manager actually is a good cup manager of just a lucky one.
I just had a quick check and compared to 5 random managers (Pochettino, Moyes, Allardyce, Hughes and Klopp) and using a 3 points for a win, 1 for a draw system Martinez has a better cup record than all of them bar Klopp.
Martinez has 2 semi's and 1 final which he won. Pochettino has 2 semi's and 1 final which he lost. Allardyce has 2 semi's and 1 final which he lost. Hughes has 6 semi's and no finals. Moyes has 3 semi's and 1 final which he lost. Klopp has 1 semi and 4 finals, winning 1.
But does that actually mean he's better than the other 4 in cups, or he's luckier?
What skills and abilities does he have that make him a better cup manager than league manager?
Like you say, motivation could be 1 thing. A good man manager who might be poor on the tactics and training fronts might be good at getting players up for a potential trip to wembley and a cup win, but not so much for an away trip to Stoke on a windy Wednesday night mid table mediocrity clash.
What else?
I'm just querying really as to whether he actually is a good cup manager therefor has a good record and if so why, or if because he has a good record people think he is a good cup manager which can be an overly simplistic way of looking at it.
It's about consistency
I've never said that Martinez has never had a good league campaign, because he has (Although most of them were in the lower leagues)
However, if we look at his return in top divisions (Which is where he will want to work if he goes back to club football) more of them were bad/stagnant than good
You could argue that happens to a lot of managers, which indeed it does, however if you look at Martinez at both Wigan and Everton, every league campaign was ultimately worse than the previous one or at very best comparable
For instance, in his four seasons at Wigan, his team finished 16, 16th, 15th and 18th
Now yes, Wigan weren't a top side but, when you consider under Bruce they had finished 11th the prior season, that represented an alarming drop off for them. The 15th place was hardly a massive jump up from 16th either. They went from a team comfortably mid table to one constantly fighting relegation, eventually ending in them facing relegation
At Everton, he finished 5th in his first season, 11th in his second and we were 13th as of his sacking. So he took a team regularly looking for Europe and left them as, at best, mid table also ran and, at worse, a club hurtling toward relegation fodder
So that's essentially one good league campaign out of seven in the Premier League
So the suggestion is that the one good league campaign was the aberration when it came to top tier football
Meanwhile, during those same seven seasons he won one Cup and also reached two semi finals, and indeed rarely crashed out in the early stages of cup tournaments. A clear feather in his cap
Therefore you could argue the cup runs were NOT aberrations, and instead argue that Martinez was good in cups but bad in the league, hence international football suits him perfectly
The proof will of course be in the pudding if/when he takes a job at a club again in a top league. He may indeed have a decent start at any new club he joins, especially if he has a strong base to build on. However, the previous form suggests that league finishes will dip and will not recover. This is why I hope he sticks with Belgium, as in that environment I genuinely think he can win something, and good luck to him if he does!