Since 1901 baseball has seen 40 switch-hitting catchers with 500 career plate appearances. If you want to deplete the potential talent pool quickly, take 1,000 people and sort by the guys who can catch, then filter out the non-switch hitters. You may have one or two potential players. We're living in the golden age of switch-hitting catchers so it seems. Jorge Posada, Victor Martinez, Jason Varitek, Ryan Doumit, Gregg Zaun, Jarrod Saltalamacchia, Dioner Navarro, and Josh Bard are playing and batting from both sides. Meanwhile Todd Hundley and Chad Kreuter aren't too far removed.
A few years ago the Rays had a catcher named Javier Valentin. Nothing special, Valentin had 435 big league plate appearances escorted by a .638 OPS. He had one good season but that's not entirely important. What is important is hit ability to hit right-handed pitching. Relative to his left-handed inability, he ripped righties. Maybe he saw the ball better, or was more comfortable, I don't know why, he just did. Later on he finally dropped the switch-hitting act and as it turns out that is the most interesting thing to take from his career. Well, that and his mustache.
With Navarro being the right-handed part of the catcher platoon, it raises the question: at what point do the Rays just tell him to stop switch-hitting all together, much like Valentin? Over the last three years here is how his splits break down:
As LHB v. RHP: .245/.312/.349 (235 PA)
As RHB v. LHP: .286/.403/.375 (67 PA)
As LHB v. RHP: .221/.282/.325 (311 PA)
As RHB v. LHP: .226/.277/.441 (104 PA)
As LHB v. RHP: .308/.361/.406 (351 PA)
As RHB v. LHP: .257/.314/.413 (119 PA)
As LHB v. RHP: .188/.227/.271 (205 PA)
As RHB v. LHP: .289/.297/.454 (105 PA)
Only 395 plate appearances against lefties with OPS nearly .100 points higher. He's obviously got a better power stroke from the right side. We've got enough of a left-handed sample to derive his ability is rather poor. Could he become worse against righties if he hits only from the right side? Maybe, but it's not like he's hitting them well as a lefty anyways.
Even if you date back a bit further in Navarro's career for some added data, you come out with career numbers that indicate he is superior as a right-handed hitter. He's even had about 20 plate appearances as a righty, versus another righty, and fared quite well. Obviously we can't pin too much on a sample size that small, but if Navarro is going to start in this league full-time again, he needs to A) fix his plate discipline, B) consider dropping the novelty approach to hitting, and focus on one side of the plate.