Howe of Fife won their own event last week and take a three-point lead over Boroughmuir into the penultimate tournament. The hosts are third but, 15 points behind, need a good day today to move into overall contention.
Hamilton will start as favourites in Pool A with Cartha Queen's Park and Cambuslang, while Glasgow Hawks and GHA are likely to do battle for top spot in Pool B. Howe of Fife and Boroughmuir will be expected to top Pools C and D respectively.
Howe of Fife won the event last year, clinching victory in an evenly matched final against GHA. Howe led 15-14 at the interval but fell behind to a GHA try before their young team came through to win 27-19 with two more tries and a conversion.
Today's opening match, between Hamilton and Cambuslang, starts at 1pm.
Pool A Hamilton, Cartha Queen's Park, Cambuslang
Pool B GHA, Glasgow Hawks, Dalziel
Pool C Howe of Fife, Greenock Wanderers, Falkirk
Pool D Boroughmuir, Kirkcaldy, Musselburgh
Standings (after 3 of 5 tournaments) 1 Howe of Fife 32pts, 2 Boroughmuir 29, 3 Hamilton 17, 4= Edinburgh & GHA 15, 6= Stirling County & Glasgow Hawks 12, 8= Perthshire & Kirkcaldy 7, 10= Cartha Queen's Park, Stirling Uni, Dundee HSFP, St Andrews Uni, Seabass Select, Greenock 5, 16 Falkirk 2, 17 Alloa 0