New user here, sorry for the super long (and possibly controversial) post.
I got my hands on an old Chicago PS 85 (buttcap code GUI) maybe six months ago, tried it out just for fun and fell in love with it. (I was a high school kid in the 1980's when the racquet came out and couldn't afford it or get my parents to buy one for me back then. I had a cheaper graphite/fiberglass midsize Wilson racquet instead, which I never liked very much as I found it too flexible. But now, I prefer the PS 85 even to my previous all time favorite, HPS 6.1 18x20).
Since then, I have been sort of obsessing over these racquets, and acquired a backup: early bumberless, buttcap code GYQ. "Chicago" or "St. Vincent"? What follows is some theory (a lot of it admittedly guesswork) based on internet research, about the early Chicago and St. Vincent production. (I know, one shoudn't pay too much attention to butt cap codes, etc., but anyway, here goes.)
The most extensive source on the origins of the Pro Staff is the TW article which, while including some valuable information based on interviews of some key Wilson engineers involved in the development and production of the model, unfortunately seems to be inaccurate in places.
The TW article claims that the Pro Staff was introduced in 1983, but it has been argued above that the introduction was actually in 1984 (citing industry publications etc.). I think it is safe to say, at least, that there was no real marketing effort from Wilson for the Pro Staff before 1984. That is, of course, not the same thing as when the production started.
Conventional wisdom is that the model was first produced in the River Grover, Ill. (Chicago), factory and then pretty soon production was moved to St. Vincent, with the specs of the racquet (at least superficially) staying the same. On the other hand, some have claimed that the very first racquets were actually produced in Belgium, even predating the Chicago production. Others have refuted this claim citing a Wilson engineer involved in the production, according to whom the brief Belgian production was for European sales only and was simultaneous with St. Vincent production.
Evidence of butt cap codes, while not conclusive by any means, seems to shed some light on all this. It has been presumed that the first letter of the code probably indicates the year of manufacture and the second letter probably the month of production. Furthermore, it is widely accepted that the third letter indicates the factory, with ‘I’ indicating River Grove (Chicago) and ‘Q’ indicating St. Vincent. If the first two letters are year and month, it can be further assumed that Wilson used alphabetical order (i.e., for year G is earlier H, and for month M is earlier than N, etc., even though for some reason they seem to have skipped some letters altogether).
If one accepts these assumptions, it looks like ‘G’ may have been the very first year of production for the Pro Staff, as I have not run into anyone (here on the boards, on internet auction sites etc.) claiming to have a racquet with an earlier code. This is also consistent with the fact that all Pro Staffs with a code ending in ‘I’ (indicating the Chicago factory) seem to have a code starting with ‘G’, with the earliest maybe being ‘GMI’ (and then there are ‘GNI’, ‘GOI’ and so forth).
But then again, there also seem to exist ‘Q’ racquets with just as early looking codes: ‘GMQ’, ‘GNQ’, ‘GOQ’ etc. Of course, a butt cap can be replaced with one from another Wilson racquet of the era, the year-month presumption may be all wrong and so on, but personally I think all this can be reconciled by assuming that the last letter only indicates the factory where the racquet was finished ready for sale (not where the frame was actually “produced”), and that very early on, perhaps from the very start of the production of the model, some batches of the raw frames produced in Chicago were shipped over to St. Vincent for finishing.
This is consistent with how Wilson seems to have operated with some of their Chicago-produced frames – according to the TW article the St. Vincent factory was initially bought by Wilson for this very purpose. This is also consistent with some knowledgeable people on this board maintaining that there are “Chicago” Pro Staffs ending with ‘Q’. (Of course, what you call such a racquet depends on definitions, but I would tend to agree that a frame produced in Chicago and only assembled and finished in St. Vincent with all the same appointments as the ones produced in Chicago from start to finish is more a “Chicago” than a “St. Vincent”. Also, there seems to be some indication that Wilson themselves were attaching “Made in U.S.A.” cards to early racquets with a code ending in ‘Q’.)
After the first year ‘G’, codes on all early Pro Staffs seem to end with ‘Q’ (‘HMQ’, ‘HNQ’ etc.), indicating that from there on (or maybe even a bit earlier) they were all at least finished in St. Vincent. It seems likely that some of these racquets were still Chicago-produced frames shipped over to St. Vincent for finishing. According to a Chicago Tribune article (
http://articles.chicagotribune.com/...ilson-sporting-goods-david-lumley-snack-foods), the River Grove racquet factory was closed in late December 1984 and its production was moved to St. Vincent. If ‘G’ indicates 1984, at least some year ‘H’ (1985) racquets could still be Chicago frames. (Even more so, if ‘G’ indicates 1983 and ‘H’ is 1984. However, as the codes with ‘G’ as the first letter seem to have many different second letters ranging from ‘GMI’/’GMQ’ all the way to at least ‘GXI’ for Chicago and to ‘GYQ’ for St. Vincent, it seems that ‘G’ was a full calendar year of production, or almost. Therefore, ‘G’ is more likely to be 1984 than 1983.)
As to the rare Belgian frames, I think the Wilson engineer remembers it correctly, as these seem to all have codes starting with ‘H’ (‘HNB’, ‘HPB’ etc.), indicating the second year of production (be that 1984 or 1985). Furthermore, the pictures I have seen of Belgian-produced Pro Staffs seem to support the claim that they were meant for European distribution only, as they lack the stickers stating weight and balance in U.S. measurements. Also, those frames also usually seem to be from European sellers. All in all, judging by the evidence, the claim that the Belgian production predated even the Chicago production seems to be erroneous.
Final point: When did the change from bumperless construction to bumper guard actually occur? The TW article claims 1984, but bumperless racquets seem to exist with codes starting not only ‘G’ and ‘H’ but also with ‘J’ (‘J’ seems to have followed ‘H’ as the letter indicating year of production, skipping over ‘I’). This would indicate that the change to bumper was later than it says in the TW article, maybe sometime in 1985 or even 1986.
Thoughts? (If someone had the tenacity to read all the way through, and did not fall asleep...)