Let me explain by reasoning out my list... there would be about 20-25 managers who have won a lot lot in europe/world football, and they all would be contenders.... so what separates them, what makes some greater than others?? Its what those coaches meant to football, how their startegies changed the way football used to be played... open any textbook on football strategies, and you will see the names of Helenio Herrera and Rinus Michels in them, coz these 2 probably chnaged the way football is played more than anyone else... they just redefined the game.
Back to my list:
1. Helenio Herrera - the "inventor" of Catenaccio!!He modified a 5-3-2 tactic known as the Verrou (door bolt) to include larger flexibility for counter attacks - and the Catenaccio was born - using the full backs (particullary Giacinto Facchetti) as wingbacks (defensively supported by the libero) to launch faster counter-attacks.
Catenaccio and its hybrids are the MOST common tactical elements of modern football, almost every manager these days uses Herrera's methods to some extent or other. Mourinho's Porto were a textbook adaptation. He also pioneered the use of psychological motivating skills -his pep-talk phrases are still legendary. He was also one of the first managers to call the support of the "12th player" - the spectators, as that was an important part of his home-away strategy. While indirectly, this led to the appearance of the first Ultras movements in the late 60s. His impact as a manager can be observed by historical nomenclature - for the first time in history, a manager was mainly credited for his teams' performances. Till then teams were credited to players, like Di Stéfano's Real Madrid, whereas Inter FC during the 60s is still referred to as Herrera's Inter. Herrera's Inter won three Serie A titles, a Coppa Italia, two European Cups, and two Intercontinental Cups. Herrera was also successful with Barcelona, Atlético Madrid, and (to a lesser extent) AS Roma.
2. Rinus Michels - the father of "Total Football"Michels is credited with the invention of a major football tactic known as "Total Football" in the 1970s, and was named "coach of the century" by FIFA in 1999 coz of the impact his brand of football had in the 70s. The only reason he is below Herrera in my list is that Total football in its pure sense is obsolete now, and that he did not get along very well with the players. Michels favoured a dominant and attacking style of play in which the offside trap played an important part, where players kept changing positions confusing the opponents. This style was perhaps born in an attempt to best use Cryuff in the best way possible, letting him roam into positions where he could do the opponent maximum damage. Rinus took over at Ajax when the club was in serious danger of relegation. When he left they were the premier side in Europe, the best. In 1988 he led Holland to their only major title, the European Championship
3. Ernst Happel: The foundation of modern attacking football Happel goes down in history as the first coach to win the European Cup with two different clubs, winning first with Feyenoord and then with HSV. He also won domestic titles in 4 different countries in europe (germany, belgium, austria, and holland)!! Infact, even his Club Brugge also reached the European Cup final... wonder what he would have done for a top team in the Big 3!! But what I give Happel the most credit for, is to "invent" the more practical hybrid of Total Football, the attacking format that the likes of Cryuff employed later in their managerial careers, and that we still see in world football. While he too used the offside trap heavily, his tactics were to make his team alternate between pressurizing their opponents and playing for possession, under no circumstances allowing the opposing team to settle in to their preferred game. His Holland lost the world cup final in 78, just like Michel's holland 4 years before, but to give Happel credit, he was working with "weaker" resources. From an evolution point of view, a Happel had to preceed a Sacchi, just like a Michels had to preceed a Happel, hence the order in my ranking.
4. Arrigo Sacchi - the architect of Milan's golden era, more importantly, attacking football's renaissance I am surprised that this choice shocked people here... Coz Sacchi did define the attacking brand of calcio, cleverly mixing Herrero's catenaccio into the Happel style of football, advancing a part of the traditional "libero" duties into the midfield (the first modern holding midfielder was born). The system he favoured was too dependent on intelligent players like Baresi, Donadoni and Rijkaard (specially Rijkaard) that were able to preserve the balance between attack and defence, using one attacking fullback in young Maldini, and the roaming genius of Gullit. As one of the inspirers of the renaissance of attacking football in the early 90's, Sacchi certainly deserves to be included in this list of greatest ever football coaches. Ask any Milan fan, and he will tell you that while Capello's record breaking Milan were awesome, they were not like "that Milan". IMO, it was a team which has had the biggest impact on football ever since I have been watching this game (mid-80s).
5. Béla Guttmann - The inventor of "4-2-4" formationThe only coach to ever win the European Cup and Copa Libertadores. He did both, TWICE!! Bela was very much a product of the Danubian School of football, or the 'Scottish System', which favoured a short-passing game with the ball kept on the ground (as opposed to English 'Kick and Rush'). Guttmann took it to another level, favouring an dynamic and attacking style of play. He worked in nearly a dozen countries including Brazil, where he was instrumental in introducing the famed 4-2-4 system, which the Brazilians would go on to use to great effect during the 1958 and 1970 World Cups. He also took Benfica to two consecutive European Cup wins (1961, 1962), breaking Real's monopoly over the championship.
By no means I am suggesting that these should be the top 5. This is just my opinion, being a keen student of football tactics and history. Just wanted to illustrate how these guys did a lot more apart from winning a lot of trophies. Sure, most of them must have stumbled on their invention due to the resources they had at their disposal (like Facchetti for Herrera, Cruyff for Michels, etc), but then there is a chance factor in every great invention... And of course there are others who also contributed a lot, most of them mentioned somewhere on this thread.... so much of this is subjective and opinion, we all understand that. But these 5 should make any top 10, that much I am convinced of.
Phew, this must be the longest post I have ever researched and written!!
Benetiz, anyone?