Leeds boss Marcelo Bielsa has admitted he was behind the Derby training ground spy incident.

Here, we look at the career and idiosyncrasies of the man they call 'El Loco'.

Pitch perfect

Bielsa is known to check pitch measurements before matches. He waits upon

deciding on a particular formation until he paces out the pitch. Bielsa's

unorthodox approach also stretches to almost obsessive use of videos - editing and analysing for each player - and allocating separate training times for different parts of his squad, with the defenders, midfielders and strikers

working alone.

Pep talk

Bielsa has no shortage of football disciples but perhaps his greatest supporter

is Pep Guardiola. The Manchester City manager travelled to Argentina for a

meeting with Bielsa in 2006 prior to taking charge of Barcelona. "My admiration for Bielsa is immense," Guardiola reportedly said. "I have never met a player who has worked with Bielsa and has spoken badly of him. For me he is the best coach in the world."

Trademark tactics

Bielsa's principles is based on aggressive pressing of the ball and intelligent positioning both in defence and attack. He has previously employed a 3-3-1-3 formation which has flummoxed opponents, while his 4-2-3-1 system demands a huge workrate, which can sometimes put him at odds with his players.

Lazio U-turn

Bielsa spent two days in charge of Lazio in 2016. He was appointed manager of the Serie A club on July 6, but quit just 48 hours later complaining that the

club had failed to recruit the players he required. Lazio issued legal action

against Bielsa for breach of contract, suing him for 50 million Euros, before

the coach resurfaced at French club Lille just over a year later.

French leave

Bielsa's last job at Lille was a short-lived affair. He signed a two-year

contract last summer but was suspended in November with Lille second bottom of Ligue 1. It was reported that Bielsa went on an unauthorised trip to Chile to visit former national team assistant Luis Bonini, who was battling stomach cancer. He was eventually replaced in December by Christophe Galtier.