This version started because of a pattern called Three Philosophers, as shown in the The Mah Jong Player's Companion system, created by Patricia A Thompson and Betty Maloney. As soon as I began to look closely at the pattern, I realized I couldn't program it in the same way I did with the National Mah Jongg League patterns. The annual count for NMJL patterns is a total of 700-800 variations on average, for all of the yearly 60-70 basic patterns.
The variation count for Three Philosophers, alone, is 339,570. So, of course, I thought "ooo, a programming challenge!"
I have developed 2 systems for practicing Mahj patterns. The first system was developed for the National Mah Jongg League patterns. It was released it in 2019. This Western system was developed to practice the patterns for 2 Western variations: The Mah Jong Player's Companion and Wright-Patterson Rules (2015) for Mah Jongg. It is still in development. Expected release date is January 2025.