A good bowler can score relatively well on a fresh house shot with pretty much anything. Sanded heavy oil ball, urethane, or anything in-between. But a good bowler can also know when to make appropriate ball changes to complement physical adjustments when the shot calls for it. Just because it's a house shot doesn't mean it doesn't drastically change by the end of the night depending on who else is bowling on your lanes. Some nights I stick with one bowling ball and barely move my feet the entire night. Other nights I end up 15 boards left of where I started throwing something highly polished or throwing an entry-level reactive because the lanes have changed so much. (And I'm a stroker, so it's even more drastic a change for someone who really hooks it!) Yeah, I could still hit the pocket and carry a lot of shots with the ball I started with, but I also am going to leave quite a few more corner pins and 4 pins simply because it wouldn't give me the same amount of margin for error that a better match-up ball would give me. That's the difference between walking away with a couple hundred bucks in jackpot money after shooting a 279 versus walking away empty-handed after shooting a 237.

So yes, it's not necessary to just change balls constantly like many people do. (I have a teammate who thinks he's a great bowler, when in fact he's not even close, and he doesn't know anything at all about physical adjustments, so he just switches balls three or four times a night without any thought process behind why he's switching to something else). But I bring four strikes balls plus plastic with me to league simply because I don't know what kind of shot I'll see by the end of the night, and my ball I use to smooth out the backends on a fresh shot probably won't be the right one by the end of the night when I see I'm bowling against a bunch of old men who have their heavy oil balls sanded to 500 and fluff them right up the track area, no matter how much I can adjust my physical game.

Define THS.  What is it?  Is your house exactly like mine?  Do you know anything about my house?  I think the notion of a THS is bupkis.  If it isn't, then I want everybody to stop asking questions like what surface, what kind of pins, what type of lane machine, etc.

If it doesn't really matter, then we should all have to use the same equipment.  Pick a weight that is suitable for everybody, maybe 14 or 15 lb and we all use the same ball, and the same drilling.

Sure the answer to your question might be for everybody to take some lessons and learn a bunch of different releases, but I'm guessing that at least 80% of league bowlers don't care.  It's a chance for them to get together with friends, shoot the breeze, maybe drink some beers, and forget about real life for a few hours.

And I can think of several thousand people that appreciate the people that buy multiple balls.  I'm sure your local pro shop is one of them, along with all the employees of the ball companies.  And I only bring that up because during the holiday I found out that one of the local shops where I used to live is closing at the end of year.  He says that people aren't buying equipment and he can't afford to stay in business on the little bit of money he is making.

Now excuse me, I have to go load my 12 bowling balls in the car for league tonight.  I like to switch every couple of frames whether I need to or not.


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Haywood

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"Let every nation know, whether it wishes us well or ill,
that we shall pay any price, bear any burden,
meet any hardship, support any friend, oppose any foe,
in order to assure the survival and the success of liberty."

--JOHN F. KENNEDY
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