Robert Lewandowski in the form of his life as he returns to Borussia Dortmund once more

When Robert Lewandowski moved from Borussia Dortmund to Bayern Munich in 2014, the five-year contract was due to keep him at the Allianz Arena until just shy of his 31st birthday.

The Polish forward was one of a number of Dortmund players to make the switch to Bavaria during the period, following Mario Gotze in 2013 and preceding Mats Hummels, who moved to Bayern in 2016.

Lewandowski arrived after scoring 20 or more goals in three straight Bundesliga seasons, and there was belief that a stronger supporting cast could help him go beyond that.

However, few could have anticipated the extent to which he would subsequently kick on, ensuring that now, nearly a year after that initial five-year deal was due to end, Lewandowski is as good as he has ever been.

It’s not as if Bayern were getting a rookie back in 2014, of course. This was a man who had single-handedly destroyed Real Madrid in a Champions League semi-final, scoring four goals to put an end to any hope Jose Mourinho had of lifting a European title with the Spanish side.

He remains one of only five players to ever score a hat-trick at that stage of the competition, and the only player to record a four-goal haul in a Champions League semi.

However, even with that in mind, Lewandowski’s achievements at Bayern - under both Pep Guardiola and his successors - have seen him step up a level despite that not seeming possible.

The stand-out moment for many came against Wolfsburg: after coming off the bench with his team a goal down, he scored five goals in the space of just nine minutes, leaving even Guardiola stunned.

While raw numbers only tell part of the picture when it comes to a footballer’s ability, Lewandowski’s are absolutely breathtaking.

He now has 40 goals in each of the last five seasons, with his effort in the 2-0 win at Union Berlin bringing up the milestone this time around in just 34 appearances - the quickest he has managed it in his entire career. He added another in the 5-2 weekend win over Frankfurt.

Furthermore, the 38 goals he has scored in the Bundesliga and Champions League this season have come from an xG of 30.4, according to FBref.com.

By way of contrast, Mohamed Salah’s xG for the domestic league and Champions League comes in at 19.5, Sergio Aguero’s is 16.0, while Cristiano Ronaldo's is 19.6.

Even Lionel Messi is only on 16.9 this season, though he topped 30 for 2018/19. Premier League top scorer Jamie Vardy's figure stands at 14.2.

How Lewandowski stacks up

Robert Lewandowski

Goals scored: 38 - xG: 30.4

Mohamed Salah

Goals scored: 20 - xG: 19.5

Lionel Messi

Goals scored: 21 - xG: 16.9

Sergio Aguero

Goals scored: 18 - xG: 16.0

Cristiano Ronaldo

Goals scored: 23 - xG: 19.6

Jamie Vardy

Goals scored: 19 - xG: 14.2

This isn’t just a case of a competent forward on an unrealistic hot streak, but rather someone who knows how to sniff out chances and how to convert them, all while playing for a team with a wealth of attacking talent.

That’s an absolutely terrifying combination.

Oh, and just for good measure, this season has also seen Lewandowski record a four-goal haul in a Champions League game for the second time in his career, helping Bayern put six past Red Star Belgrade.

Only one other player has achieved the feat, and when you’re standing alone with Lionel Messi it tends to be a sign you’ve got things right.

Bayern Munich have tasted defeat five times in 38 games this season, winning 29 of the others. That’s pretty good going by anyone’s estimation and since Hansi Flick took charge, they've improved immeasurably.

Take out the games where Lewandowski has failed to score, though, and you’re left with two defeats from 31. If Lewandowski scores, Bayern are likely to win.

He’s already in double-figures when it comes to go-ahead goals in the Bundesliga alone this season, setting Bayern on the way to victory in two of their first three league victories and scoring the opener when they beat Borussia Dortmund 4-0 in the first Klassiker of the season back in November.

"Robert is in the form of his life, he's in peak condition and full of confidence," Bayern boss Hansi Flick said in February ahead of the Champions League meeting with Chelsea.

Even before that game, in which Lewandowski scored to clinch a devastating 3-0 away victory, it would have been hard to argue.

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