These rules are useful heuristics, but a good graph has a purpose, and its parameters are chosen accordingly. So, while Tufte may favor a wide sunspot graph to

These rules are useful heuristics, but a good graph has a purpose, and its parameters are chosen accordingly. So, while Tufte may favor a wide sunspot graph to emphasize the weak downward slope, my advisor (a solar scientist) would have slammed me for that. We already know that there's a weak downward slope. What we care about is the absolute magnitude of the peaks. Tufte's graph is useless here.