Although most people agree that a number is a number, and no matter what your story is as to "how close" the spin was, if your number didn't come up the ball might as well have landed in the salad bar for all you care. But the truth is that a ball landing "close" can actually be significant to your play!
A roulette wheel's physical characteristics aren't often a factor when you're picking favorite numbers such as birthdays or sports celebrity's jersey numbers. But when you are playing a BANK of numbers, a ball spinning out of your last number and into enemy territory can be serious business. First, let's consider a player that has bet on EVERY OTHER number on the wheel; next to each winning pocket is a losing one, and so on. Nobody will be surprised when the ball spins into (or out of) a winner - it's just the nature of the game. Nobody will be surprised when that guy loses ten spins in a row. Whay? Because he has LOSERS EVERYWHERE!
But on the other hand, imagine a player that has bet on EVERY NUMBER from the single zero to the double zero. All he has to do is have the ball land ANYWHERE ON THAT HALF OF THE WHEEL and he's a WINNER! Now that player can't lose ten in a row as long as the ball lands on an entire side of the wheel JUST ONCE in that run! So what does this have to do with fret heights?
Arguably, a dealer that is not trying to cheat and does not have a severe "signature" (see other page) should probably have their "decay" land in various parts of the wheel. Even more so because dealers often try to "randomize" their own spins by varying spin velocity or - even more commonly - look away when they spin so as not to see where the wheel is when they release, and even delay the throw by a random number of seconds. (Entirely separate post) So, assuming that the dealer has done their best to randomize where the ball will first fall out of orbit and strike the wheel, we can bring the discussion to the point that FOLLOWS the first click of the ball against the frets.
When the ball's orbit decays and it first strikes a wheel with high frets (I'm talking to YOU, Imperial Palace!) the ball will rarely spend much time at all bouncing around the wheel, and will many times CLICK into place immediately - very near the point of initial contact.
Conversely, when a ball first strikes a wheel with low frets it can spend a lot of time clicking and clacking along, sometimes even SKATING across the top of the frets as if it's barely being obstructed at all! One could argue that at this point, any wheel bias at all right down to grease, tilt, a worn-down fret and slight breeze... all could potentially cause a systematic loss. This would be catastrophic if you were investing in a pattern bet and were prepared to go full bankroll in waiting for that sector to come up!
So all things considered, when betting sequential runs or sectors of a wheel, look for tall frets! It's nice to reduce the number of variables involved when betting with (or against) the physics of a particular wheel!