Tottenham Hotspur are a side seemingly unstoppable at the moment, having added to their unbeaten run recently with a spirited win at Luton Town. In the Premier League, Ange Postecoglou has made his side unbeatable, and toppling Manchester United and Liverpool whilst also recording a fine away draw at Arsenal should stand as further proof.

Whilst the football is enthralling, and the mindset is one completely altered for the better, it is arguably his transfers which have been the most impressive, with some of his key acquisitions having already grown into hugely integral figures in north London.

James Maddison needs no introduction for his fine start to life in N17, with his offensive impetus and creative energy making him one of the division's most in-form assets. Then, Saturday's match-winner Micky van de Ven is another who seemingly goes from strength to strength, adding a goal to the impressively solid foundation his presence has ushered in.

Should the Lilywhites maintain such proficiency in the market over the coming windows, the sky truly is the limit for their progression under the former Celtic man.

It seems that Daniel Levy has learnt from his high-profile blunders of the past, and is now desperate to ensure he avoids replicating them by acting with decisiveness when a target is identified.

However, that has not always been the way they have operated…

Who is Spurs' worst-ever signing?

Outlining Spurs' worst-ever signing is a tough feat, but unfortunately not because there is a shortage of options.

If someone were to pose such a question to a group of fans, it is highly likely they would all throw different answers at the interviewer. "Tanguy Ndombele for £63m," one might shout. "Richarlison cost £60m and has only scored two Premier League goals," is another that would be justifiable.

When stretching even further back, the likes of Roberto Soldado, Erik Lamela, Paulinho and David Bentley would again make completely viable options.

However, with regard to pound-for-pound profligacy, it would be hard to look beyond Vincent Janssen, who whilst might not take the top spot, certainly would be a fierce contender given his ill-fated stint in north London that lasted three miserable years.

Joining from the Netherlands, having enjoyed a hugely proficient spell for AZ Alkmaar, the 29-year-old was signed as some ample competition for Harry Kane, who had burst onto the scene with a string of fine goalscoring campaigns, but was yet to offer enough to suggest it would be even close to the longlasting success eventually earned.

Therefore, the Dutchman was brought in, leaving Mauricio Pochettino delighted with his business. The current Chelsea boss would note: "Vincent is still very young and his potential is massive to develop,” said Mauricio of the 22-year-old. “He has a profile that fits perfectly for us. He has quality in the box and he’s a striker that likes to fight and work for the team. That is perfect for us."

The Argentine would put particular emphasis on that closing statement, reiterating: "His human profile is perfect for the team, we always care about that. In general, he’s a player that fits the team."

In the end, his claims would be proven devastatingly wrong, and the 6 foot flop would leave having scored just six goals across 42 appearances. Even a loan spell in Turkey could not reignite his career with Spurs, eventually departing for Mexico.

In fact, despite starting his temporary tenure at Fenerbahce well, he still came under fire from Turkish football pundit and journalist Hincal Uluc, who accused the 29-year-old of cheating: "Whoever brought Janssen to Turkey better take a good look in the mirror. We have enough frauds in the league as it is, now we have brought in another one from abroad.

“He threw himself on the on the floor for a penalty. Janssen hasn’t come here to play football, he is here to get opposition players booked with his diving."

Since then, Janssen has never really reached the heights of that sensational 32-goal season in the Eredivisie, that spurred Levy to spend big on him.

How much did Vincent Janssen cost Spurs?

Joining in July 2016, as the Lilywhites had just mounted the most unlikely of title pushes before Leicester City came out as victors, it was expected that his presence would help add some key goals into a side already boasting plenty, whilst also potentially helping Kane reach even loftier heights.

2018/19

€8m (£6.9m)

33% decrease

2017/18 (loan to Fenerbahce)

€12m (£10.3m)

14% decrease

2016/17

€14m (£12.1m)

N/A

All stats via Transfermarkt

However, it is fair to say that he failed in both of these ventures, with his £18.6m price tag far from merited.

In fact, that debut term saw an abysmal league return of just two goals, neither of which were particularly consequential.

How much did Vincent Janssen earn at Spurs?

Having joined for a decent fee, without costing too much, it was a deal made even sweeter by rather affordable wages given his youth and lack of experience at the elite level.

It is likely his inability to take to English football that hampered his career and made what should have been a huge bargain a lucrative nightmare. Even his £34k-per-week wages turned sour, as he amassed a further £3.5m from the two years in which he actually took a salary directly from the club.

Therefore, in total Janssen cost Levy £22.1m. To then compare his weak goal tally with this figure, and it works out that his true cost to Levy was a whopping £3.6m per goal.

How much did other Spurs players earn?

Whilst his wages were relatively inconsequential when compared to the rest of the squad at the time, such a cut-price should have made this acquisition one of their finest. Even if his £34k-per-week salary was very similar to the £35k-per-week that Kieran Trippier earned, as a far more consistent performer at full-back, via Spotrac.

The figure he earned was also only £21k-per-week less than that of Dele Alli and Mousa Dembele, two of Pochettino's most important assets.

At the top of the earning charts for that 2016/17 term were rightfully Harry Kane and Hugo Lloris, both of whom earned a modest £100k-per-week. Lamela's £80k-per-week salary likely marked the biggest robbery of that particular group, although Janssen's anonymous contribution would suggest otherwise.