\(Z\)-Cyclic Wh(28)

Bill Butler1, Stephanie Costa2, Norman J. Finizio3, Christopher Teixeira4
1238 Pine Ridge Loop Department of Mathematics Durango, CO 81301
2Department of Mathematics Durango, CO 81301 Rhode Island College Providence, RI 02906
3Department of Mathematics University of Rhode Island Rhode Kingston, RI 02881
4Department of Mathematics Rhode Island College Providence, Ri 02906

Abstract

Whist tournament designs are known to exist for all \( v \equiv 0,1 \pmod{4} \). Much less is known about the existence of \(\mathbb{Z}\)-cyclic whist designs. Previous studies \([5, 6]\) have reported on all \(\mathbb{Z}\)-cyclic whist designs for \( v \in \{4,5,8,9,12,13,16,17,20,21,24,25\} \). This paper is a report on all \(\mathbb{Z}\)-cyclic whist tournament designs on 28 players, including a detailed summary of all known whist specializations related to a 28 player \(\mathbb{Z}\)-cyclic whist design. Our study shows that there are \( 7,910,127 \) \(\mathbb{Z}\)-cyclic whist designs on 28 players. Of these designs, \( 2,568,510 \) possess the Three Person Property, \( 240,948 \) possess the Triplewhist Property and none possess the Balancedwhist Property. Introduced here is the concept of the mirror image of a \(\mathbb{Z}\)-cyclic whist design. In general, utilization of this concept reduces the computer search for \(\mathbb{Z}\)-cyclic whist designs by nearly fifty percent.

Keywords: Whist Tournaments, Z-Cyclic Designs, Triplewhist Designs, Three Person Whist Designs, Balanced Whist Design