It's just Scotland's luck that they wait years for a top class left-back and then two come along at once.


Both Kieran Tierney and Andy Robertson have been entertaining Premier League audiences of late and Scottish manager Steve Clarke has the unenviable task of fitting both of his star men into a workable starting XI.


But what if he could only pick one?


Would Clarke go for the Arsenal's Isle of Man-born flying Scotsman or Liverpool's rival fan-ruffling assist machine? 90min took a deep dive into each players strengths and weaknesses to find out.



Versatility


Tierney is comfortable in a variety of different positions

Versatile players are a vital commodity, particularly at international level when the disparity in players' abilities are often dramatic. It's also good to have players who can play multiple positions at tournaments when a squad size is limited.


Not that Scotland have had to worry about that much in recent years...


In this category there is only one winner, Tierney. The former Celtic man has only been at Arsenal for a season and yet he has already been deployed in several different roles. Left-back, centre-back, left wing and midfield - Tierney can do it all.


Robertson meanwhile, has largely remained at left-back or wing-back throughout his career so far, though this is perhaps more of a reflection of the settled nature of Liverpool's backline than his own lack of versatility.



Defending


Andy Robertson loves to get stuck in

Ah, defending. Though it may not seem like it at times, a modern day left-back does still occasionally have to do a bit of this now and again.


Each player has a fiery, competitive edge and both are fans of a meaty tackle and an aerial duel. Overall though, Robertson is the superior defender. The Liverpool man is leading Tierney in Premier League tackles completed per 90 minutes by some margin (1.6 compared to 1.2) and also enjoys an advantage in headers won.


Positionally, Robertson similarly enjoys an advantage. 31.8% of his pressures end in him winning the ball compared to Tierney's 29.3%, while the 26-year-old's superior experience means he is rarely caught out of position.



Crossing


Sorry, this is another no contest. Of course it's Robertson. In fact, you'd be hard pressed to find a better left-footer crosser on the ball in world football, to be honest.


As a right-back, it must be so intimidating to know that Robertson only needs half a yard of space to drop a picture-perfect cross straight into the corridor of uncertainty. It's this sort of razor sharp precision that has seen him pick up over 20 Premier League assists in the last two seasons.


That's not to say that Tierney is not a fearsome crosser himself - far from it. Since nailing down a spot in the Arsenal first team he has regularly put in more than five crosses a game, though none of them have led to an assist as of yet.


Maybe Robertson needs to take his young apprentice under his wing, just as he did to 90min earlier this season...



Dribbling


Robertson is an accomplished and athletic dribbler

A key reason behind Liverpool's ability to progress the ball up the pitch so quickly is the thrust that Robertson provides at left-back.


Watching the snarling Scotsman in full gallop is quite the sight to behold. He possesses a devastating combination of acceleration and subtle close control which allows him to race upfield with ease.


On average Robertson has progressed the ball 201 yards per 90 in the Premier League this season, figures that leave Tierney (96.4 yards) trailing long behind. Even accounting for clear difference in attacking approach play, this shows a clear winner in the dribbling stakes.



Overall


Robertson comes out on top in this battle of the Scottish left-backs

Although Tierney's encouraging post-lockdown form has got Arsenal fans purring he has some way to go before displacing Robertson as Scotland's first choice left-back.


His advantage in the versatility stakes is cancelled out by the Liverpool man's superiority in every other area required of the modern day defender.


Better begin preparing for an international career playing out of position, Mr Tierney. Good thing that versatility's there...