From mid-December to late February, the Heart of Midlothian hype train was picking up pace. Excitement gathered as the team’s lengthy winning run, punctuated by a 2-2 draw at home to Ross County just before the turn of the year, continued unabated. Week after week another opponent would fall by the wayside, and supporters were positively giddy about the direction the team was heading in.

It's hard to blame them. The run started with a thoroughly well-deserved 2-0 victory at the unlikeliest of venues, Celtic Park, and Hearts would go on to win 10 out of their next 11 games, recording a total of six clean sheets in the process. Steven Naismith’s side shot up the table, pulling clear of the chasing pack and making third place theirs to lose. For a while, they were even closing the gap with Glasgow’s big two. Some fans couldn't help but wonder - what if Hearts had started the season in a similar fashion? Could there have been a three-way race for the title?

When Hearts travelled to Ibrox in February, much of the pre-match discussion was centred around the gap between the Gorgie club and the Old Firm. Just how big was it? Could Hearts be closing it?

Those questions were seemingly put to bed in emphatic fashion as Philippe Clement’s men racked up a commanding 5-0 win on an afternoon where Hearts were decidedly second-best. But just as one swallow doesn’t make a summer, we should be wary of reading too much into a single bad day at the office. Hearts’ eventual canter to third suggests that the team have managed to put some distance between themselves and the rest – but are they closing the gap to the Old Firm?

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Facing the Old Firm

The gap between Celtic and Rangers and the rest can be difficult to quantify. Things like bank balances and the league table certainly give us a good idea, but it’s how that materialises on the park which is of the most significance. In order to see how close Hearts are getting to the Old Firm, we must first recognise a simple truth: matches involving Celtic and Rangers are different, and the rest of the league often change their tactical set-up when facing them.

If we want to know if Hearts are getting treated with a similar sort of reverence, then we need to understand how Premiership teams set up when playing the Old Firm. The graphic below shows how Hearts and each of the other nine Premiership teams have performed in games against only the big two this season, using some key team metrics that give us a rough statistical profile of each team. The black bar represents the league average for the other nine clubs when playing Celtic or Rangers.

There will always be areas where certain teams truly excel but Hearts are outperforming the average in just about every metric and are often leading the way. The goal difference and the difference in xG are above average but both are still comfortably negative and could be a lot better. Going by the data, the Old Firm are usually worthy winners when playing Hearts. Naismith’s side hit more shots than anyone else but with a relatively low xG per shot, suggesting that there are a few speculative efforts in there. For all the shots Hearts have against the big two, the number of clear-cut opportunities per 90 minutes is only marginally better than the league average.

Hearts enjoy a larger share of the ball than the rest, typically recording around 41 per cent possession and completing more passes than any other Premiership team. They rank highly for deep completions (passes within 20 metres of the opposition goal) and are slightly above the league average for crosses into the box. Hearts’ pace to goal is on the lower end of the scale, implying a more patient approach when other teams are going direct, and only Hibernian attempt more dribbles. Hearts also get more joy than most further up the park; Kilmarnock are the only team with more deep progressions (passes and dribbles into the final third).

It’s a similar story off the ball. Passes Per Defensive Action (PPDA) is a metric that measures how many passes the opposition play before the ball is won back, and it’s used to give an indication of how quickly a team regains possession. Celtic and Rangers average 15.5 passes before Hearts win it back; only Motherwell and Livingston retrieve it faster. Naismith’s side slightly trail Livi and St Johnstone for the amount of pressures, but it’s worth bearing in mind that Hearts enjoy significantly more of the ball. Were we to adjust for possession, the men in maroon would be the standout performer in this regard. It’s a similar story with counterpressures (pressures within five seconds of losing the ball), where Hearts are head and shoulders above the rest.

So, what does this all mean? In short: Hearts don’t play like many of their Premiership contemporaries when facing Celtic or Rangers. Naismith’s side see more of the ball and are more effective out of possession, and that can only be a good thing. The league average represents failure (the Old Firm tend to win these games, after all) and the further away from it you can get, the better your chances of giving the gruesome twosome a game.

READ MORE: Analysing Hearts attackers: Forrest's dribbling, Oda's shooting, Grant standout

Facing Hearts

Going by the numbers, Hearts’ performances against Celtic and Rangers largely stand out from the rest of the league. But this is just one piece of the puzzle. In order to get a deeper understanding, we have to consider how other teams fare when playing against Hearts. The graphic below shows the data from Celtic and Rangers’ meetings with Hearts this season, as well as showing how the other nine teams got on against the Gorgie. The black bar again represents the average of the remaining nine clubs.

We want Celtic and Rangers to be the outliers here. The more teams clustered around the league average, the better. If Hearts really are pulling away from the rest of the pack, then there should be a healthy gap between the Old Firm’s statistical output and that of the remaining nine teams, illustrating the gulf between Glasgow’s big two and the rest.

The results make for interesting reading. Celtic and Rangers comfortably lead the way in most categories, and there are a few areas where the likes of Kilmarnock, Aberdeen and Hibernian impress. This tells us that this trio of clubs are still managing to make their presence felt during games against Hearts, and downplays suggestions of a gap forming between Hearts and the rest. But take a look at the clubs who usually find themselves towards the lower end of the scale in each category. Many of the teams in the bottom half of the table struggle to get going against Hearts, and their output against the Gorgie club isn’t a million miles away from what they tend to produce against the Glasgow clubs.

In a nutshell, this means that clubs operating towards the bottom end of the Premiership are starting to treat Hearts with the sort of reverence that’s usually reserved for the Old Firm. The effect lessens the further up the table you go, and Aberdeen and Hibs are often the outliers (games between the pair and Hearts are usually fairly even affairs, statistically speaking). But, barring those notable exceptions, the data suggests that Hearts are being treated with more respect. Their opponents don’t see as much of the ball as they would like, don’t use it as effectively as they could, and struggle to create and score chances as a result. Many, but not all, teams are finding Hearts harder to play against – and that can only be a good thing.

READ MORE: How Hearts have evolved this season: Defiant defence, more control and set-pieces

How Hearts play

We’ve looked at how teams play when facing the Old Firm and Hearts but there is still one last angle to consider, and it’s arguably the most important one of all. How do Hearts play against the rest of the league, and how similar is it to the sorts of displays that Celtic and Rangers put in?

The chart below shows how Celtic, Rangers and Hearts each performed in fixtures against the remaining nine teams, and the black bar again represents the average output of the rest of the league when playing each other. Essentially, the difference between the average and the Old Firm is what the gap looks like in a statistical sense. If Hearts are closing in on the big two then there’s an argument to be made that the gap is shrinking; if Naismith’s side are closer to the average, then the reverse is true.

Now, the league average for goal difference and xG difference is always going to be zero (the nine teams all played each other, so they cancel each other out in these metrics) but we can still see that Hearts have some work to do on this front. Hearts’ goal difference when facing the rest sits at 0.53 (around a third of what the Old Firm usually record) but the xG difference is only 0.2. This tells us that while Hearts usually create more and better chances from open play than the opposition, the margin of superiority isn’t as strong as it could be. The data also suggests that Hearts have been significantly overperforming in front of goal in these types of games. In short: Naismith’s side tend to take their chances against the rest of the league when they come along, but a few more opportunities wouldn’t go amiss. This is also reflected in the number of shots and clear shots attempted per game. In both categories, Celtic and Rangers comfortably lead the way. Hearts, meanwhile, are performing marginally better than the league average.

Going by the shooting and chance creation data, the gap is as big as it’s ever been – but there are other areas that make for encouraging reading for those of a maroon persuasion. Take possession, for example. Celtic lead the way on 71 per cent, followed by Rangers on 65. Hearts aren’t trailing the Ibrox club by all that much, averaging 59 per cent against the rest of the league, and it’s a similar story when we examine each team’s passing accuracy. Again, Celtic lead the way with Rangers not far behind, and then there’s Hearts – still a few percentage points behind Clement’s side, but a few ahead of the league average too. Deep completions follow a similar pattern – Celtic are way out in front, but Hearts aren’t too far behind Rangers.

We can see Hearts being a little more patient than the rest of the league when they are attacking by looking at the team’s pace to goal. They are only marginally behind Rangers in this sense, but it should be remembered that Clement’s side are a particularly direct team by the standards set at Ibrox. It’s notable that Hearts are below the league average when it comes to hitting crosses into the box, and only just ahead of the average when it comes to deep progressions. In both areas, Naismith’s men fall well short of what the Old Firm tend to produce against the rest of the top flight.

Hearts’ work off the ball stands out, however. They still have some work to do to match the Old Firm’s level when it comes to PPDA, but they are performing significantly above the league average. This means that Hearts are winning the ball back relatively quickly. Naismith’s side also attempt more pressures per game than the Old Firm, but this is down to the fact that they spend more time out of possession. Counterpressures, though, are another intriguing area. Celtic lead the way but Hearts are only trailing the champions marginally, and the men in maroon out-perform Rangers and the league average here, highlighting Hearts’ impressive work in transition.

READ MORE: Eight Hearts stats and what they tell us about Steven Naismith's side

Small steps in right direction

Going by the data, then, it would appear that Hearts still have some way to go before they can start being considered in the same bracket as the likes of Celtic and Rangers. Crucially, though, Hearts regularly find themselves operating somewhere in between the Old Firm’s output and that of the average Premiership team. There’s a strong argument to be made that Hearts are being treated differently by the rest of the league, albeit not to the same extent that the Old Firm are.

The differences between Celtic and Rangers’ output across key metrics compared to the rest of the league – these are what represent the gap. All the additional resources, the huge squads of multi-million pound players, the blue-chip managers – the differences between the bars on our graphs are what it all boils down to on a matchday when the players cross those white lines. This season we have seen Hearts starting to pull away from the rest, to take a few tentative steps towards the gruesome twosome. There is still some way to go, but an old Chinese proverb springs to mind. A journey of a thousand miles begins with a single step. And Naismith and his players are certainly on the right track.