While Sir Alex Ferguson ultimately achieved his aim of aim of "knocking Liverpool right off their f---ing perch," there was a period spanning over two years where his Manchester United team could not beat Gerard Houllier's Liverpool.

Between December 2000 to January 2002, Liverpool won all five of their games against their arch rivals. During a recent conversation with old foe Gary Neville, former Liverpool defender Jamie Carragher suggested the Reds had found a successful way of playing against United -- thanks, in part, to a Liverpool scout's history with Ferguson.

The scout Carragher was referring to was Alex Miller. Miller, who spent nearly a decade at Liverpool in many roles, was a teammate of Ferguson's at Rangers for a short period, but their relationship continued as the Scottish pair moved into management.

"Alex and I would speak regularly when I was in Scotland," Miller told ESPN FC. "I would get a phone call on a Friday night when he was Aberdeen manager. Me and Alex have no problem. To be fair, Alex helped me get my first job at St. Mirren. It was him who recommended me."

Miller joined Liverpool in 1999 following a nine-month pursuit from Houllier. Initially reluctant to take a role that did not involve day-to-day coaching, Miller was given the loose title of director of scouting.

His first role at the Merseyside club was focused mainly on closely studying upcoming opponents before disclosing his observations to Houllier and the Frenchman's coaching staff. The Scot would then cut and present a 12 to 15-minute video of the opposition to the team during a meeting at Melwood, as well as having the license to speak to any player individually in private.

To prepare for matches with United in particular, Liverpool's coaching staff would relay the importance of outnumbering United's players.

Alex Miller (C) made a big impact at Liverpool under Gerard Houllier. Nick Potts - PA Images/PA Images via Getty Images

"It started with his [Ferguson's] Aberdeen team," Miller said. "Now they all speak about playing between the lines and coaches try to get people in between the lines. Alex had his team between the lines all the way back then.

"He had a 4-4-2 set up. What he tries to do is get so many between the lines that it's so difficult for you as a team to combat that because if you draw a line across a page, there's maybe six lines.

"His back four, two central defenders sort of split -- not wide like they do now, but they split a wee bit. The two full-backs pushed on maybe 10, 15 metres. Their two central midfield players split. One would come to the ball -- Roy Keane -- and one would go in an advanced position -- Paul Scholes.

"Their two wide players -- [David] Beckham and [Ryan] Giggs -- would then be in another line. You've got one holding midfield player, one advanced midfield player, you've got Beckham and Giggs in between these two. The two strikers always played one and one.

"What we did to combat that was we tried to get three versus two all the time. We had sort of a 4-1-3-1-1 formation -- one man off a striker.

"One striker picked up the area of their withdrawn midfield player. Whatever side of the pitch the ball was on, we would have a full-back, a midfield player and one of the front players to get over to the side if it went to the side. They had a full-back and a wide player, so we had three versus two. If it went the opposite side, we had three versus two.

"We always had to have three versus two. That's 18 years ago, even more, and no team was getting in between the lines at that sort of stage. That's why it was so difficult to sort of combat them."

Around a year into his time at Liverpool, Miller took on further responsibility when scouting potential transfer targets was added to his brief. In that department, too, he found himself in direct competition with Man United.

"I looked at Gerard Pique and I tried to get him," Miller revealed. "The Spanish delegation he was with at a youth tournament, I think it was his grandfather who was the delegate for the Spanish federation. Well he wouldn't give me permission because I think Man United were already in at that point.

"I brought Cristiano Ronaldo [suggested to Liverpool as a signing]. That's water under the bridge, [but] I recommended him and saw him at a youth tournament.

"Diego Forlan, I turned him down before United even got to him. At the final hour when United were going to sign him, Gerard Houllier asked me whether I was sure. I was positive he would be more suited to Spain or Italy."

Forlan did struggle to adapt to the English game, scoring just 10 goals in 63 Premier League appearances for United between 2002 and 2004. That said, Forlan went down in United folklore for his goal-scoring exploits against Liverpool -- scoring twice at Anfield in a 2-1 away win.

Any transfers from Liverpool to United or vice versa were simply off the table. Gabriel Heinze's desired move from Old Trafford to Anfield in 2007 was blocked by Ferguson, who did not want to sell to an arch rival, with a Premier League arbitration panel later ruling that United did not have to sell the left-back to Liverpool.

In fact, the last transfer between the two clubs was back in 1964 when Phil Chisnall moved to Liverpool.

"He would never let them go," Miller said. "It was real red-hot stuff. It really was. They always had to beat Liverpool and we always had to beat United. When we started to get a hold of them as you say, then things changed slightly."

The increase in hostility was similar, Miller believes, to that of Rafael Benitez and Jose Mourinho's when the competition between Liverpool and Chelsea was at its fiercest both domestically and in Europe.

"He [Mourinho] was nice as night to us when we first met him, but when we started to beat Chelsea, he changed," Miller said. "He wasn't so open and talkative. He would say hello and all that, but it wasn't as if he was your best friend."

Incidentally, during his scouting missions, Miller had previously looked at two players who would go on to become Chelsea stalwarts during the Benitez-Mourinho rivalry.

"I tried to get John Terry to come," the Scot said. "It was 2003 when Chelsea beat Liverpool for the last place in the Champions League.

"It went to the final day and they beat us at Stamford Bridge. After the game I went to speak to John Terry to try and get him. How I did it was, I went up to him in the corridor and asked him for his autograph. He said yes. As he was signing it I said: 'Could you put your mobile phone number? Gerard Houllier would like to talk to you.'

"He put his agent's number and said to talk to him. Gerard Houllier spoke to his agent on the bus. I think he just used us to get more money out of Chelsea. I also had Petr Cech, but at that moment in time we were trying to sign Chris Kirkland. I went to a game to watch Milan Baros and Petr Cech was making his debut.

"I then went to Argentina, I think it was in 2001, the Under-20 World Cup. You could have got him for a song. He was with Chmel Blsany and then he moved to Sparta Prague and then he moved to France [to Rennes]."

Those players were two of thousands that Miller had observed all across the world as part of his work at Liverpool. His frequent travels around the globe earned him Gold reward cards for nearly every major airline.

Chuckling while recalling this particular anecdote resulting from his travels to Argentina to look at players such as Pablo Aimar and Walter Samuel, Miller said: "I bought my wife a leather jacket in Argentina. I came back and thought it would fit her, but it was far too big for her. I went back three weeks later and changed it in the shop again and got her a smaller one!

"I would sometimes fly to Argentina on a Friday night. I would maybe get there 9.30 a.m. on a Saturday. I would watch six top-level games on Saturday and Sunday. When we played Roma, I followed Roma in January and we played them in February. I followed Roma seven Sundays in a row. I'd go out on the Sunday and come back on the Sunday night."

Alex Miller changed role under Rafa Benitez. Getty Images

Miller's role would, ultimately, change when Houllier was dismissed at the end of the 2003-04. While Benitez replaced Houllier and brought in his own staff, Miller stayed on Merseyside became a first-team coach following recommendations from a number of senior players within the Liverpool dressing room.

"Gerard was disappointed in me for not leaving when he left. But at the end of day, they got payoffs. I didn't get a payoff and I needed a job," he said. "I was on holiday in America when Rafa told me to come back. I came back and he just asked me what my role was. He put 4-4-2 up on the board and asked me how I would play against them.

"I wasn't intimidated by him because I knew I was good tactically. I said: 'Well you can't just say that,' which threw him a wee bit. I said: 'Is my team as good as yours? Are my players as good as your players? Are my players as quick as your players? OK, I'm going to do this because you're going to have a problem there.'

"This to-and-froed. The only difference we had was the defending of the game with the strikers."

Miller delivered the prematch videos to the squad during the season in which Liverpool won the Champions League in 2005. He stayed alongside Benitez for another three seasons before the chance to financially secure his family's future arrived when Japanese side JEF United Chiba offered him the manager's job in May 2008.

"It's a fantastic club, Liverpool," Miller concluded. "In the end, it wasn't the same club that I joined. You had two people on the gate at the training ground and they decided to relieve one of their duties to cut costs. The guys are getting paid about £150 a week. The guy had been there 25 years. What was that about?

"I was 59 at the time and money had never been a motivator. But I'd seen a few changes at Liverpool and I went: 'They'll just put you out of the door, just the same as the rest.' I just thought that I'd look after my family."