What Exactly is "The Database"?

The other day I wandered back through early posts to see when I started collecting Jerome Gambit (and related) games in a database for this blog. My first mention of a special base came in the June 20, 2008 post.

In a post about a week later I noted that the database contined 950 games. The post included the following information

In all about 7% are over-the-board games, 12% involve computers (person vs computer or computer vs computer), 2% are traditional (snail mail) correspondence games and 79% are games played on the internet (various time controls).

Some time later I reported on the "Evolution of The Database", which I would like to reprise

It is fun to look back and see that in the early days of this Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) blog, I bragged of having a database of whopping 950 Jerome Gambit Games.  Of course, today, the modern version of that database (aka "The Database") has over 1,000 games played by DragonTail alone.

In the beginning, in order to expand the number of Jerome Gambit games that I had access to, I offered a PGN file of 210 of the games mentioned on this blog, (not all Jeromes) in exchange for any games sent to me. The offer quickly expanded to almost 500 games, and on June 10, 2009, the first "birthday" of this blog (celebrating a year of posting every day) I offered a "present" of over 1,100 games.

I continued digging for gold, sometimes with great success. 

Instead of "games posted on this blog" I switched to developing a PGN database of Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+), Blackburne Shilling Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4 4.Bxf7+), and Semi-Italian Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.0-0/4.Nc3/4.d3 Bc5 5.Bxf7+) games. 

By the time I offered the "New Year's Database" it contained over 17,000 games.This year's version, renamed "The Database" and offered on January 1, 2011, contained over 22,500 games, and included the above-mentioned variations, plus the nameless 1.e4 e5 2.Nf3 Nc6 3.Bc4 Na5 4.Bxf7+. 

Today, The Database contains about 25,000 games. (It is still available to interested Readers at no cost).

I have not given information about The Database since February, 2015, so I thought I would bring Readers up-to-date.

I have updated The Database with games from FICS (Free Internet Chess Server) through November 2015. It now contains 53,740 games.

The basic Jerome Gambit position, after 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+, appears in about 12,112 games. White scores 45%

The Italian Four Knights Jerome Gambit, 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Bc5 5.Bxf7+, appears  2,368 times. White scores 38%.

Interestingly, the Semi-Italian Four Knights Jerome Gambit, 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 h6 5.0-0 Bc5 6.Bxf7+, appears only 124 times, but White scores 67%. Note the "power" (or lack of) ...h6.

This is reflected in the Semi-Italian Jerome Gambit, 1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 4.0-0 Bc5 5.Bxf7+, appearing in 170 games, where White scores  65%. Interestingly, with 4.Nc3, in about 130 games, White scores only 54%.

The Blackburne Shilling Jerome Gambit, 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4 4.Bxf7+, appears in about 5,170 games, with White scoring 56%.

A large number of recent examples of the Abrahams Jerome Gambit, 1.e4 e5 2.Bc4 Bc5 3.Bxf7+, have been added. There are 17,137 examples, and White scores 51%.

Because the line continues to show up, and is worth knowing, the nameless 1.e4 e5 2.Nf3 Nc6 3.Bc4 Na5 4.Bxf7+  appears in The Database 2,197 times, with White scoring  72%.

There is also a large selection of Jerome-ish lines, featuring, for example, an early Bxf7+ by White. Some Reversed Jerome Gambit games have been included, as well.

Of course, all statistics need to be taken with a grain of salt (see "Caveat" for some fun, though) but it is relevant to note that about 95% of The Database is drawn from 15 years of FICS games, making much of it representative of online club play. Some reasonable conclusions can be drawn.

I can email The Database at no charge to anyone who requests it.