I was actually taking the current and the last four seasons into account, so the term half a decade was probably too vague.
Leverkusen is currently 2nd in the league while Schalke is 5th. The former have never finished outside the top 4 in the above mentioned time frame. Schalke in the same time finished 2nd, 14th, 3rd and 4th.
The one year sticking out for the Blues is of course 2010/2011. In that year they had their amazing CL run (ultimately falling to United in the Semis) and their cup win. One big reason for their success was that they concentrated basically everything they had into the cup campaigns resulting to them finishing barely above the relegation zone that season in the league.
The German cup win was of course a success, but a closer look at that campaign actually does not make it look that impressive. They won every game except the final vs. surprise team MSV Duisburg (2nd league team at that time) only with one goal difference. Even the earlier fixtures vs. the lower class teams FSV Frankfurt and Aalen were fairly close affairs. The three games leading to the final were all nail biters. Augsburg and Nürnberg were defeated with very late goals and while they scored early vs. Bayern Munich (their only really serious competition), that game turned into a game towards one goal really quick. In none of the three games they were really the better team, but they fielded the best man in every game: Manuel Neuer. I sometimes lost count how many times he saved his team with world class saves there. In hindsight not many cared how they won that silverware, but I was not only talking about results and trophies in my earlier comparision. I was talking about performances.
Personally, I think that Leverkusen overall played the better football over most of that period. Their tactics were cleaner, their play style better organized. There is also of course the point that a lot of Schalke´s success was built on sand, especially in the Magath era, which drove them into red figures and resulted into a considerable amount of debt, whom a lot is still burderning them at the present.
They do have one thing going for them, though. They have perhaps the best academy in Germany, bringing up players like Manuel Neuer, Max Meyer or Julian Draxler. This helped them financially in the past (the Neuer deal was extremely needed at that time) and could do so in the future.
? We paid a huge amount of money for a goalkeeper with one year left on his contract, signed Altintop 6 or 7 years ago, who was hardly special and then you probably have to go back to the 80's when we signed Thon to find another player who moved to us.
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