I said I'd do this for a while now, and since I'm up and bored I'll do it now. There have been many (and I mean MANY) questions about adding lead tape and so on. Their effects, their benefits, suggestions on locations, and so forth. In this thread, I have posted most of my knowledge on the subject, some of which I will reiterate here. http://tt.tennis-warehouse.com/showthread.php?t=295789 I will try to outline most of the information to simplify the reading and understanding process. I'm not the best writer (English is my worst subject and "basic math" is my best), so it still might be a bit foggy. So feel free to ask questions for clarification. Hopefully I won't be the only one to answer because that would put a heavy burden upon myself to constantly check here and answer everything. With this, I can also easily edit information should I learn anything new or a previous concept be wrong (I am human after all). Hopefully all edits will be for the former reason, not the latter. I might also edit this from time to time just to reorganize the information and make it more readable, because I'm too lazy to do it on the first go. So let's begin shall we? I) Racket Specs: A) Swingweight - Higher swingweight means more power. You want this number to be as high as you can manage for the entirety of a match. Expected range of values go from like 220 to 400 kg*cm^2. http://twu.tennis-warehouse.com/learning_center/swingweight_calc.php B) Twistweight - Higher twistweight means more forgiveness and stability on off-center hits but lowers mobility. (You can think of it as widening the sweetspot.) You want this to only be as high as you need. Expected range goes from 10.5 to 20 kg*cm^2. http://twu.tennis-warehouse.com/cgi-bin/twistweight.cgi C) Recoil Weight - Higher recoil weight means it's easier on the arm on impact (basically, higher means you're less likely to get arm injuries). Same with twistweight, you only want this to be as high as you need, but you can go a little higher to be safe. I'm not going to speculate on the expected range, but 170+ kg*cm^2 is good if you expect to see a lot of high level shots coming your way. D) mgR/I - The square of angular frequency, meaning a higher value has the racket coming around faster. However, increasing it affects mobility negatively due to the extra weight and shift in balance point. Or you take away power by lowering swingweight to increase mgR/I. It's one of those fine balance sort of specs if you even want to pursue it. Travelerjam has done a ton of stats on this and concludes an optimum value to be in the 20.6-21.2 range. (Apparently higher is better if you're shorter, and lower if you're taller.) I'm not an expert on this, and there are very few articles on this. Feel free to tinker and see if it works for you or not. http://www.racquettune.com/MgR_I/ II) General Lead Placement Locations: A) 12 o'clock (top of the hoop or under the bumper guard, preferably the latter) B) 11&1 or 10&2 (stringbed side) C) 3&9 o'clock (stringbed side) D) 6 o'clock (Some people do this) E) Throat or handle (Lead on the handle is placed UNDER the replacement grip, or better yet, take off the buttcap and put it inside the frame once you know your final specs) F) Buttcap III) How to Increase Target Specs: A) Swingweight is measured relative to 4 inches from the buttcap. The idea is that people were expected to hold the racket from that location, so they measured it from that location. Weight placed anywhere above or below that location increases swingweight. However, to further customize it for yourself, when adding weight, if you want to minimize the perceived increase in swingweight you feel, put the weight in the center of where you hold the racket - so closer to 1-1.5 inches from the buttcap for more advanced players. Anyways, the swingweight increases exponentially based on distance from the 4 inch mark (or where you hold the racket, but to keep things simple from now on, we'll just assume you hold the racket from that location). Increases in swingweight are equal to the added mass in kilograms, times the distance from the 4 inch mark (in cm, so distance from the 10.16 cm mark) squared. So 3 grams at the 5 inch mark is a 3 kg*cm^2 increase in swingweight, while under the bumper for a 27 inch racket, it's ~10 kg*cm^2 (0.003kg*58cm*58cm). The same amount of weight at 3&9 gives ~6 kg*cm^2 increase (which varies based on racket since for some rackets this location is higher and for others it's lower). B) Twistweight is basically the same thing as swingweight, but measured side to side from the vertical axis of the racket. The more weight you add towards the sides, like 3&9, the number goes up. The farther to the side you place it, the number goes up exponentially (which is why most oversized rackets feel more forgiving on off center hits; it's not new tech, it's physics). However, note that almost any weight you add to 12, 6, or even the handle (short of being compressed to the size of a spec of dust) will increase twistweight. If you use long strips of lead at 12, you're giving yourself a decent boost in twistweight. So to avoid that, use shorter strips, if possible, if you want to avoid raising twistweight. As such, this tends to be a secondary priority to swingweight. C) Recoil weight is, again, similar to swingweight, just measured around a different axis (these are all different moments of inertia). To keep it simple RW = SW - m*b^2. RW is recoil weight, SW is swingweight, m is mass in kg, and b is distance from the balance point to the 4 inch mark in cm (so balance in cm minus 10.16 cm). So basically, higher swingweight means higher recoil weight linearly, higher mass lowers recoil weight linearly, and a lower balance increases recoil weight exponentially. Even simpler, either have a high swingweight or a low balance point. D) Balance is altered simply by adding weight AWAY from the balance point. The farther away, the more drastic the change. I could tell you how to calculate changes manually, but it's probably just easier on everyone if I just link you this: http://twu.tennis-warehouse.com/learning_center/customizationReverse.php. Otherwise, the formula is l' = (LM - lm)/m', where LM = final balance * final weight lm = previous balance * previous weight m' = weight to be added E) mgR/I is increased by increasing mass, raising the balance, and/or lowering the swingweight. Obviously, most combinations of the three aren't favorable. Increasing mass and balance means lower maneuverability. Lower swingweight means less power. Lowering swingweight and raising mass means lower recoil weight and therefore comfort (good luck to your arm). Lowering swingweight and raising balance also lowers recoil weight. One location of compromise is 7 inches from the bottom of the racket. Increasing weight by 17 grams gives about a 1 kg*cm^2 and has less of an effect of lowering the balance.