Recently, criticism has been leveled at the amateur level of the SL deshi. We can all agree, a little more professional approach to the concrete areas of SL would go far in deflecting such criticism.

I suggest we make a collective effort to 'cite' any information we add to SL joseki. What does a joseki citation entail? How about:

1. The first professional game the joseki appears in
2. Further pro games which show the joseki in context

I don't know about everyone else, but I learn by example.

I think this kind of 'citation' would take our joseki reference to a whole new level of awesomeness. :)

I argued strongly against doing this kind of thing on the Systematic Joseki pages, but here's my rough argument again.

The points I made then, addressing both when it was last played and the relative frequency of a given jeongseok:

• Joseki are Overrated: Knowing which is the most common reply is good, but is it really important to know that this particular joseki is played in 2 percent of pro games with the prior situation without knowing what the rest of the board looks like?
• Database Biasing: Is that 2 percent of games in the last year, five years, ten years, or fifty years? Each of these numbers has a different value and none of them are particular useful unless you are examining a particular pro's style compared to other pros. Does the database cover all pros, or is there a bias away from less known pros? These biases matter to anyone doing serious research, and they undermine the value of statistics that are collected.__
• Updating: This is not some database collected long in the past. This is an evolving data set. Joseki are a living set--particularly with the Koreans on the scene--and the pros have trends. I've made it a personal project to keep a small set of professional Korean players updated (about 12 of them) because some of them hadn't been updated in years. That's relatively trivial and anyone can do it with a little practice. Joseki require access to specific databases and the software to scan them, then it requires updating every page in the library, which leads me to the next point:
• The Size of the Database: There are tens of thousands of joseki. For creating the database this isn't so much a problem--we can do it one page at a time and the page content only changes when a variation gets added. But keeping them updated? That's another question entirely and there's really no way to cleanly keep things updated.

The first time a joseki was played is kind of nice to know and, unless there is a correction, it never changes. But the last time? I lack the ambition to even keep track of that for my favorite players (and the expertise to do so even if I had the time), much less for several hundred players playing games all of the time with tens of thousands of possible joseki.

I'd like to add to that a few additional comments:

• Just because it occurs in a pro game does not mean that it is jeongseok. Sequences are constantly being re-evaluated and reviewed. Sometimes a new move will become jeongseok, but sometimes a refutation is found.
• If something is older and less frequently played today, it does not imply that there is anything (necessarily) wrong with it or that it is not still considered jeongseok--simply that the modern style has moved away from it for the moment (e.g., playing a knight's move instead of a one-space extension when there's a knight's approach to a 4-4). Sometimes that 30-year-old sequence has been refuted, sometimes it simply gives away too much influence or is too calm for the modern style, or sometimes it has simply fallen out of favor because the winds have changed direction.
• As you say, context is very important. One game is often insufficient to gain that context though, so if you are interested in studying a particular jeongseok in context the base way to do it is to go over many many games that it has occurred in, rather than just looking at the last few.