Everyone knows football is a funny old game – Saint and Greavsie copyrighted the expression sometime in the last century – yet as Swansea City examine the possibility of replacing the uncomplicated Garry Monk with Marcelo “El Loco” Bielsa it is worth reminding ourselves that the business of football coaching can be even odder.

Cast your mind back just over five years to the 2010 Champions League final in Barcelona, for instance. Facing each other that day were José Mourinho, attempting to win a treble with Internazionale, and Louis van Gaal, attempting to win a treble with Bayern Munich. No Italian or German team had even won a treble before, so this was uncharted territory for both men, although Mourinho already had a European Cup under his belt with Porto, from his native league, while Van Gaal had done the same a little bit further back with Ajax. There could only be one winner – and it was Mourinho, who said his goodbyes the same night and began preparing for Real Madrid. Van Gaal, who had already managed Barcelona, left Bayern the following season and later took over Holland, who had some success in the last World Cup.

The point is obvious. These are not Johnny-come-lately type coaches, callow chancers or enthusiastic hopefuls, they are proven winners at the top of their game. At least Mourinho ought to be at the top of his game, unless three years trying in vain to catch Barcelona took more out of him than anyone imagined. He is only 52 and won the English title last season. Van Gaal is 12 years older and has perhaps been slowly declining since his initial glory years with Barcelona, a fact Manchester United would have been aware of when they sought a stopgap after David Moyes, but the Dutchman was still better qualified than most available alternatives. Given that United now wanted someone to steady the ship short-term rather than stick around for a decade or so, Van Gaal was a reasonable choice.

Yet he, like Mourinho, has just seen his team beaten by Bournemouth. Mourinho is in charge of the worst title defence in memory and, although it seemed unthinkable at the start of the season, now appears to be embracing the possibility that another sudden Stamford Bridge exit could be on the cards. That is unlikely to happen at United, who were quietly briefing their satisfaction with Van Gaal even as the club were sliding out of the Champions League and playing some of the dullest, most ponderous football anyone could remember, but the fact is that Champions League football next season is by no means certain at Old Trafford, and United are currently only occupying fourth place in the Premier League by virtue of Tottenham’s inability to mount a convincing assault on the top four.

Just by beating Newcastle United on Sunday Spurs could have gone ahead of Manchester United on goal difference, instead they contrived to lose at home to one of the season’s laughing stocks. That may seem harsh, and perhaps it is, considering Newcastle had put Liverpool’s revival under Jürgen Klopp into perspective a week earlier, yet before those two results the situation on Tyneside had become so desperate that Kevin Keegan was being mentioned as a possible saviour. Again. While Keegan may have his limitations as a tactician and touchline problem solver – this is not a secret, even the man himself has admitted as much – his sheer love for Newcastle would stir up everyone’s emotions again and put some much‑needed pride back into performances. Long retired he might be but Keegan gets Newcastle, it was being said, in a way that Steve McClaren just does not. Except now he does, apparently. This is what is weird about football coaching. No matter how intricate the tactics get, no matter how convoluted the theories or complicated the formations, games can still be won by firing up the players at half-time.

This is so old school a technique it predates even Keegan but mere motivation, getting players to give their all and run through a metaphorical brick wall, was supposed to have been put out to grass long ago. That is why Keegan did not last long as England manager, or indeed anywhere after his initial success at Newcastle. He found the formula hard to repeat. Not only was it difficult to succeed against organised teams with players who knew exactly what was expected of them in each part of the pitch, it was hard to keep his own players stoked up when results began to go against them.

The same thing might happen to McClaren yet, two good backs-to-the-wall results do not constitute a successful season, but at least the manager has located some character and backbone in a side that had appeared to lack both for much of the last few months. “The noise in the dressing room was great, even though we were a goal down at half-time,” McClaren said of his players at Spurs. “Everyone was saying: ‘Let’s fight, let’s keep going.’”

What that probably means, one suspects, is that the noise in the dressing room at half-time in previous matches has not been all that great, with players meekly accepting their fate or being cowed into silence by the size of the task ahead of them. That would certainly explain some of the performances. Fair play to McClaren for turning it around, though it remains to be seen whether the buttons that bring the best out of Newcastle can be pressed for the remainder of the season. Whatever happens he has just posted impressive results against two of the brightest young coaches in the Premier League – and if he has done it by the charmingly old-fashioned method of instilling some pride in the shirt in a squad that has not always appeared to share a common purpose, then it appears he gets Newcastle after all.

He might get Newcastle, in fact, more than Van Gaal gets Manchester United. The Dutchman is famous for having a philosophy, which however much he bangs on about it in press conferences does not seem to be getting through to his players on the pitch. McClaren would not profess anything so grand-sounding but appears to have finally made a real and effective connection with his players, exactly what Mourinho has been struggling to do all season. Chelsea and Manchester United fans must have briefly envied their north-east counterparts over the past couple of weeks. Newcastle have also been the butt of many jokes this season, yet they have just stood up for themselves and made a start at stopping the rot.

• The headline and standfirst on this article were updated on 17 December 2015 to reflect better the general nature of the piece