Great Question! First, welcome to the board and the Virginia thread. The "Tier" thing is just a bit of terminology. Lots of folks play boxes/combos on numbers, so there is a handy tool on this site called a "deflating tool." Suppose you have a list of numbers from somewhere, for example, the workup numbers. What you might want to know is whether any of those numbers have other combos or straights or what in the list. For example, here are tonight workup numbers:
Date - 023 039 052 055 060 073 088 091 132 180 201 204 255 261 294 320 434 461 480 484 495 500 508 538 544 565 581 609 661 673 676 715 720 725 734 800 832 841 867 882 892 899 952 965 968 970 971 972
072 Followers - 009 139 235 248 290 346 346 355 359 366 388 405 514 524 531 551 557 613 652 830 837
Sync - 005 013 017 032 058 093 123 168 195 217 253 254 269 298 341 371 407 410 472 487 488 494 494 501 525 525 538 564 572 574 583 598 600 604 616 631 645 652 695 709 721 736 755 765 767 780 793 826 831 836 870 897 899 906 906 913 942 957 979 983 986 999
That's a bunch of mess, right? So I drop all that in the deflating tool to see if there are combos/straight hidden in there and the result is this:
Tier 3
023(032,320) 255(525,525) 538(538,583) 609(906,906)
Tier 2
005(500) 039(093) 058(508) 060(600) 123(132) 139(913) 217(721) 235(253) 254(524) 294(942) 298(892) 346(346) 494(494) 557(755) 564(645) 572(725) 613(631) 616(661) 652(652) 673(736) 695(965) 709(970) 780(870) 899(899) 968(986)
Tier 1
009 013 017 052 055 073 088 091 168 180 195 201 204 248 261 269 290 341 355 359 366 371 388 405 407 410 434 461 472 480 484 487 488 495 501 514 531 544 551 565 574 581 598 604 676 715 720 734 765 767 793 800 826 830 831 832 836 837 841 867 882 897 952 957 971 972 979 983 999
So, the "Tier 3" numbers are combos with a total of 3 numbers in the list.
The "Tier 2" numbers are combos with a total of 2 numbers in the list.
"Tier 1" numbers are combos with a total of 1 number in the list, like 009, for example.
Hope this helps.
Again, Welcome!