Tape in your thumb hole. Sounds like your thumb hole is not snug enough. Your thumb may have shrunk.

I am having a problem with loosing the bowling ball during the swing. Can't seem to keep a good grasp. At times, it feels like the thumb slips alot. Causing a gap between the index finger and bowling ball or slip at the pinky finger. Can't get confident on the shot when this happens, unable to maintain consistency. Any suggestions on how to maintain a better or good grasp on the bowling ball during the swing would be greatly appreciated and helpful.

I see a lot of power players bend their pinky finger with the finger nail on the bowling ball. How does this effect the grip and why is it done? Is it painful to do?

Thanks in advance.

I agree with CC.  Since we are starting to get to the coldest time of the year, your hand can be prone to shrinking.  Another thing, is if the thumb feels good when you put it in but slipping during the swing, it could also be a pitch issue with your thumb hole.  Is this only happening with one ball or all your balls?

I have tape in the thumb hole and at times I still feel like I am slipping. Bowled last night to practice and noticed that I am slipping moreso where the thumb grips the bowling ball. This isn't happening to all my equipment, but enough of it to think it is a problem. Is there something to help at the thumb for grip?

I'll play around with the thumb pitch and see what happens. I'm ok with doing all this, since I have been out of bowling for quite awhile and trying to get myself back into form. I guess it's not as easy as it looks to just come back and bowl with high expectations.

Thank you all for your help and suggests and comments.

I use Valentino Franken Tape and it gets a bit slick at times.  I'll go to the rosin bag for this.  A quick LIGHT tap of it on your ball should do the trick OR tap the padded side of your thumb on one. 

What type of tape are you using and where in the thumb?  You can use alcohol or rosin for the thumb.  They sell those alcohol wipes that you could use to clean the oil off your thumb/hole but the alcohol may leave your thumb slicker.  Use a piece of the 'grippy' white tape in the front part of the thumb hole.  Ask your driller about changing the thumb pitch towards more forward or less reverse.  Another thought - how often do you change out the thumb tape?  If you are using the white tape, could it be worn?

I use white tape, but I think it is slicker than the thumb slug. I mostly put the tape in the back to take up space. Then there are times I put it in the front to help the thumb come out quicker, but that was in the past not now. Now wondering if the thumb slug is slick and if there are other thumb slugs that are tackier...need to look into this.  =)

I haven't kept up on all of the tapes currently on the market, but it used to be that there were two main types: Black and White.  The black tapes were usually thinner and slicker.  The white tapes were usually thicker and textured for a better gripping surface and usually placed in the front part of the thumb hole if more grip was required.  That is why I asked if the tape was worn, the white tapes over time could become slicker due to wear of the textured surface.  The Magic Carpet is like velcro, thick and cushy so it gives way to the thumb allowing a tighter fit and air is still allowed to pass through so you don't have the suction effect and sticking.

And yes, there is a difference between the two main types of thumb slugs but I don't remember which was slicker, someone else will have to provide that info.