Nothing is ever certain in Serie B, a league so notoriously volatile that predicting its outcome is about as simple as winning the lottery.

Calcio’s second tier is living up to its reputation this season, with a 10-point blanket covering 14 teams from fourth-placed Cremonese to Sudtirol, who are currently 17th.

If the race for the play-offs promises more twists and turns than a Netflix series, the plot in the tussle for automatic promotion has been surprisingly linear so far with Sassuolo and Pisa setting a relentless pace and Spezia desperately trying to hang on to their coattails.

There is nothing surprising about the Neroverdi‘s performances this season. The Emiliani were a near-unanimous pick for promotion favourites in the summer, courtesy of a squad that is far superior to their rivals in both quality and depth. After a relatively slow start, Fabio Grosso’s men have lived up to expectations, swatting aside almost everything in their path in their bid to return to Serie A at the first time of asking.

Conversely, few expected Pisa to be challenging for promotion and certainly not in this fashion. The Tuscans led the table for three months until the end of November and have never been outside the top three in Serie B save for their draw against Spezia on the opening day of the season. It is a remarkable transformation for a club that last played in Serie A in 1991 and finished 13th last term with a negative goal difference, just five points clear of the relegation zone.

Sacked by Salernitana in February after just five months in charge, Filippo Inzaghi has made an immediate impact in Tuscany.

Pisa have hitherto tied their colours firmly to the mast of counter-attacking football and have the second-most prolific attack in Serie B behind Sassuolo, averaging almost two goals per game, despite losing last season’s top scorer Mattia Valoti, who returned to Monza after his loan spell ended.

An insatiable goalscorer in his playing days, Inzaghi has adopted a different approach as a manager, with goals shared across his team. Matteo Tramoni, arguably Pisa’s player of the season so far, has nine goals to his name, while summer signing Alexander Lind has scored six goals and Gabriele Piccinini has contributed with four goals from midfield, while centre-back Simone Canestrelli has found the net three times.

Meanwhile, Nicholas Bonfanti chipped in with five of his own, before being loaned out to Bari last month.

His replacement, Denmark Under-21 international Henrik Meister, arrived on loan from Rennes, along with fellow loanees Markus Solbakken from Sparta Prague and Leonardo Sernicola from Cremonese. After spending over €12m (£10m) on players in the summer, the Tuscans have tightened the purse strings in January, which speaks volumes for the quality of Inzaghi’s work.

Pisa’s new-found attacking flair this season has come without sacrificing their defensive solidity. The Nerazzurri have conceded 20 goals in 24 matches so far, the second-best defensive record in Serie B after Spezia and only Marco Bleve and Stefano Gori have kept more clean sheets than Adrian Semper’s nine this term.

Inzaghi has turned Pisa into a team capable of winning matches in different ways. Against Sassuolo on Boxing Day, the Tuscans played the league leaders off the park in a 3-1 win, while the 2-1 victory in Palermo on Friday evening came on the back of a superb defensive effort.

“We’re making life difficult for everyone,” the former Juventus and AC Milan striker said. “I have an extraordinary group of players who give each other confidence, and I’m very proud of that.”

Pisa’s resurgence under Inzaghi is vindication for Superpippo, whose coaching career has ebbed and flowed.

Back-to-back promotions with Venezia and Frosinone, were offset by disappointing spells at Milan, Bologna and Salernitana, but Inzaghi looks to have matured as a manager.

“I have almost 350 games now as a professional coach and clearly you are always learning something because there is always something to learn,” he told Sky Sports last month.

“I think a coach must evolve and grow over time to succeed.”

The future looks similarly bright for Pisa off the pitch, where Alexander Knaster’s investment is paying off.

Four years after the American purchased a 75 percent stake in the Nerazzurri, the city council is working to sell the Arena Garibaldi stadium, where Pisa are unbeaten this season, to the club and plans for a new training centre have also been approved.

With an average attendance of just under 8,500, Pisa ranked 12th in Serie B this season in terms of spectators through the turnstiles, but the figure also represents 85.7 percent of capacity, by far the best ratio in the division.

“This investment is merely the first step in a long-term project to elevate this club to new heights, both on and off the field,” Knaster said when he took over the club.

So far, he has kept his promises on and off the pitch. Should Inzaghi restore the Nerazzurri to Serie A, he and Knaster may become as iconic in Pisa as the Leaning Tower itself.