How can someone find their Morphy number? The Morphy number is a measure of how closely a chess player is connected to Paul Morphy (1837–1884) by way of playing chess games. It's analogous to the Erdős Number for mathematicians.
People who played a chess game with Morphy have a Morphy number of 1. Players who did not play Morphy but played someone with a Morphy number of 1 have a Morphy number of 2. People who played someone with a Morphy number of n have a Morphy number of n+1.
In my case, in the early 1980s, I played Jonathan Penrose in a simultaneous exhibition, the cosmic significance of which was unknown to me at the time. Penrose is one of the few living MN3 players, having played Savielly Tartakower in 1950, who played James Mortimer in 1907, who played Paul Morphy himself &quot;hundreds of times&quot; from 1853. So that gives me MN4. A bit lucky: if I hadn't got that connection to Penrose, I might be hard-pressed to find my number.
Jonathan’s brother is the celebrated physicist, Roger Penrose.
So how does someone go about finding their Morphy number more systematically? Has anyone data-mined chess games databases from this perspective? Have any results been published? What are the paths implied in the Wikipedia article linked above from the MN1 to MN2 to ... to MN5 players listed there? And what's the expected MN for an active player today?
Has anyone else here managed to figure out their MN?
You'd have to find a list of players Morphy has played. Then, you'd research as many players who played each of those players. This can all be done by searching by player in a large database. Eventually you'd have a large tree, and the problem comes down to an optimal search algorithm.

You'd search "branches" with a more likely chance of giving you a small Morphy number. This means looking at players who have played more games over their career. For example, if some player A was one of Morphy's opponents who played the most games, you'd look at him first. Then, find one of Player A's opponents (call him B) who played the most games in his lifetime, and look at him first. If doing this recursively with B never leads to you (or gives a poor Morphy number), go on to C: the opponent of player A who played the second most games. If eventually you find all of Player A's opponents don't lead to you, meaning Player A isn't connected to you, go on to the opponent of Morphy who had the second most games.

But it's still a massive job to search. Even if you find a link to yourself, you need to prove/justify that it's the smallest link. Perhaps you could organize all these players into a tree and write a program to efficiently search it.