I hurt my right shoulder several years ago, so I've been playing with bowling lefty for the better part of the last decade, so it's not necessarily anything new, it's just nothing I've taken seriously up until recently. I've bowled a league here or there lefty just to give my right arm a break, but never put any real effort into it before now. Right arm just continues to get worse so I made the switch for good in August. Rather big difference in bowling league and actually trying to get "good" or competitive.
The two sides are wildly and shockingly different, at least in my opinion. Everything about them is backwards or upside down. The easiest way to explain it is that the left side plays like the right side did on the nationals team shot last year. At first it's like oh hey, awesome, super clean sharp reaction. Then you realize that's not necessarily a great thing. I have to pay a lot more attention to transition on the left side than I did on the right, because just like the nationals team shot last year, you can wreck the shot and completely block yourself out if you're not careful. Wherever you play, even on an easy house shot, you have about 3ish boards maximum to work with. However, the clean and sharp reaction also means you have zero miss room inside. You miss in, it hooks, there's no push in the middle, and none of this getting deep and fading it like you can do on the right side. If you'll notice in my video, with the exception of a few shots here and there, no matter where I laid the ball down, my breakpoint was 5-8ish.
On just about everything, you have to start a few boards inside of where you want to end up, and then move OUTSIDE as the lanes transition. On the right side, it's just start wherever you feel like and chase the shot inside as the track burns. The first thing that happens on the left is that your backends get soft, so you have to square up. Generally in just a 3 game set for league or a tournament, you won't ever move inside like I did on the video, but I filmed bits and pieces throughout practice and threw 198 shots in total on just that pair, so I beat up the lanes to the point I HAD to move deep, but again, moving deep on the left side is undesirable because it just seems to hook more the deeper you move.
Just like on the right side on the nationals team shot last year, the guys that started too deep or didn't work the shot in before they moved royally screwed themselves, and it works the same on the left side. The reaction IS better on the left side overall I think, but I also have about half the area to work with that I do on the right side of the lane on a symmetric pattern. Start a bit inside, then make 1-1 moves further out, in addition to balling/shelling down, using the backend carrydown as a shim, and you're usually set on the left side. Yeah, when the shot is good on the left, it looks like they're untouchable, but if you pay attention, they've worked to get it there, and they're also being very accurate.
HOWEVER, I'm also not saying that righties have the world and lefties have it so hard . . the challenges are different, but I think overall the right side is more universally understood, and things on the left side have been slow moving towards "equality," if you want to call it that, so it's no surprise to either see lefties dominating or righties dominating any given tournament or house pattern depending on what it all looks like. I think overall that lefties have the advantage on house patterns in a regular league IF they're good, but the majority of symmetric sport patterns favor righties. I'm also still learning a lot, I don't have this mastered by any means, but I've been working very hard at it.
Overall, I tend to give the nod in overall difficulty or inequality to the lefties, it seems like more skill is required to achieve the same "success" as can be achieved on the right. I've seen righties that have no clue what they're doing, they just have a great physical game, and their averages are higher than their lefty counterparts. However, I'd also have to argue that a smart lefty with a marginal physical game will be better than a smart righty with a marginal physical game. I'm not sure they can ever truly make it equal, but asymmetrical patterns are emerging or becoming more prevalent, and I think that's a step in the right direction. Sorry for the novel, but that's what I do . .