THE words echo down the years. “There are only two causes of real trouble,” said my maw. “Stupid people who think they are intelligent. That’s the first.”

And the second? “Centre halves who let the ball bounce.”

In an era when Donald Trump fits snugly into the first category, one can consider that the second group is becoming extraordinarily overcrowded. It is difficult to be a defender nowadays, whether it be one that lets the ball bounce instead of heading it into the stratosphere or one who simply finds that the modern game is nowhere to be in the face of overwhelming odds.

Extraordinary scrutiny will be placed on the players who will form Scotland’s defence against Lithuania tonight. This is because we are perceived to have a defence as mobile as the Maginot Line though marginally less effective. The criticism levelled at such as Grant Hanley and Russell Martin is of such a magnitude that one would have thought they were the Laurel and Hardy of international football instead of a Championship duo trying to match, at times, Championship League strikers.

But it must be said that Scotland could lose a goal to a team of horses never mind an international side. The reaction to goals from Gibraltar and Malta can never be described as one of shock.

It is, however, hard to be a defender now. Once the ball was firmly at the bloodied feet of the uncompromising (sometimes spelled psychotic) centre-half but now the skill set is such that defenders have to multi-task desperately. (And thanks to HR for that last sentence) Some, a very few, can carry this off but there is the perception that with Scotland there is more chance of a clean sheet at an impromptu sleepover with the remnants of the chimpanzee tea party.

The problems for defenders are now universal. There is a series of alterations to the game that has conspired to render the defender’s job as difficult as trying to explain just how Trump can be contending for the title of most powerful person on the planet.

The first is that defenders can now longer cripple attackers without retribution. The outlawing of the tackle from behind, in particular, has been to the enormous benefit to attackers. They can now receive the ball without fear of being brought down with all the ruthlessness and subtlety of a combine harvester.

Similarly, defenders can now be booked or even sent off for the first bad foul. Once referees allowed defenders a “free hit”. This, particularly in the sixties and seventies, was sometimes a “hit” in the contract killer sense. Some old-time defenders remember these days of tolerance and when booked for an early foul remonstrate with the officials pointing out that this was their first foul. This has, of course, has the same logic as Gavrila Princip appealing for clemency because Archduke Ferdinand was the first aristocrat he shot.

There have also been tweaks to the rules that have also worked against defenders. The first is the back pass law. There were no possession stats in the old days but I bet Liverpool goalkeepers could have amassed upwards of 80% of the total by fielding back passes from such as Alan Hansen. Defenders could take a breather, reform the lines and relax simply by giving it to the keeper. No longer. A back pass, at best, just means the centre-half has to sprint wide to receive the ball yet again with a pack of forwards harrying him as if they were lions and he was a gazelle with a dodgy hamstring.

The offside rule, too, has also confounded defences. They sometimes give in to the temptation to drop back to mark that striker who has strayed so far behind them he can only be spotted with the aid of a telescope. This creates a back four that is not a line but more a squiggle.

But, most awfully, they are now told they must “play out from the back’’. This is the ultimate insult. Attackers are quicker than defenders because speedy players when young are told to play up front. Defenders, too, are not naturally good passers because good passers when young are told to play in midfield.

So the humble defender is now told to track runs by guys who are faster than him, only to pass back to the goalkeeper as an exit strategy rather than a panic manoeuvre, and take the ball forward with all the authority and serenity of Franz Beckenbauer on ecstasy. Simples.

It is why defenders at every level deserve sympathy rather than condemnation. They are facing the equivalent of Genghis Khan and his hordes armed only with a nice line in diplomacy.

The surprise is not that defences let in goals but that, on occasion, they do not. Even Scotland’s. It is worth remembering that Gordon Strachan’s finest did not concede against Georgia or the Republic of Ireland at home in the last non-qualifying campaign.

But what are their chances of doing so tonight against Lithuania? This observer is going to hope. This is a match that Scotland have to win. It’s as simple as Donald Trump.

Though plans to adopt his defensive approach and build a wall along the 18-yard line have been ruled out on the grounds that football may be a funny game but it leaves insanity to Republican candidates.