What is a POWER BOX wager?
 Available on TwinSpires for singlerace exotic bets.
 "Power Box" wagers include all possible combinations between TWO OR MORE sets of runner position selections  while also removing any duplicate combinations.
 With Power Box wagers, players select a set of runners for EACH position of the bet (e.g. 2 positions for Exacta, 3 positions for Trifecta, 4 positions for Superfecta, etc).
 A key attribute of a Power Box wager is it allows players to easily target specific runner combinations  instead of covering every possible combination between all selected runners (like an ordinary BOX bet).
 That is, a Power Box can restrict the covered runner combinations to always contain some primary runner(s) of interest which MUST finish on the winning ticket (top2 for Exacta, top3 for Trifecta, top4 for Superfecta, etc.).
 The Power Box ticket wins if one runner from EACH of your runner position selections (e.g. "1" with "2,3" with "4,5,6") finish in any position of the bet (e.g. top2 positions for Exacta, top3 for Trifecta, top4 for Superfecta, etc).

For example, a Trifecta Power Box ticket "1 with 2,3 with 4,5,6" covers 36 combinations where:
#1 MUST finish among the top3 finishers, and
#2 or #3 MUST finish among the top3, and
#4, #5, or #6 MUST finish among the top3.
How can I build a Power Box bet?
Building a Power Box bet is similar to building other singlerace exotic bets. After selecting a singlerace exotic wager type (Exacta, Trifecta, Superfecta, etc), simply select Power Box from the list of available bet options (STRAIGHT, KEY, BOX, KEYBOX, POWER BOX) and define which runner(s) will be included for each position of the bet (e.g. 3 positions for Trifecta and 4 positions for Superfecta).
Players can select the same or different set of runners across EACH position of the bet. As always, the more runners you select, the larger the ticket size and cost.
When does it make sense to make a Power Box wager?
Power Box wagers can make sense when you want:
 To reduce the ticket cost/size of an ordinary BOX bet without removing runners and/or
 To target multiple runners to "run well" (i.e. finish on the winning ticket... top3 for Trifecta, top4 for Superfecta, etc) with a boxstyle bet
That is, Power Box wagers make sense when you're NOT looking to target runners "in a specific position" on your ticket (e.g. only on top, only in the third position, only underneath, etc).
 For example, with a Trifecta Power Box, you might want to target ticket combinations where a single PRIMARY runner of interest must finish in the top3, and one of three selected CONTENDER runners must also finish in the top3, and one of three LONGSHOT runners must also finish in the top3.
 Since a Power BOX is defined by a set of runners for EACH position of the bet (e.g. 2 positions for Exacta, 3 positions for Trifecta and 4 positions for Superfecta), the Power Box provides a convenient way to intelligently target only specific runner combinations in a boxstyle bet.
Scenarios wellsuited for a Power Box wager include:
 When you want to combine some runners in a boxstyle bet but you also want to reduce the ticket size/cost by "targeting specific combinations" of those runners ... e.g. target only those combinations that require a designated PRIMARY runner(s) of interest MUST finish on the winning ticket (top2 for Exacta, top3 for Trifecta, top4 for Superfecta). [see Example#1, #4 & #5 below]
 When you have a single PRIMARY runner of interest that you seek to combine with other selected runner sets in a boxstyle bet (e.g. you want to target combinations which combine your PRIMARY runner with a set of CONTENDERS and/or a set of LONGSHOTS). [see Examples#1, #2B, #5 below]
 When you have TWO PRIMARY runners of interest (sometimes called a "DoubleKey") that you seek to combine with some other runners in a boxstyle bet... that is, you want to target combinations where both of your PRIMARY runners MUST finish somewhere on the winning ticket but you're not looking to key any runners in any specific position (e.g. only on top, or only underneath, etc). [see Example#2A, #2B, #2C below]
 When you want to target all possible combinations containing exactly one runner from each of your selected runner groups in a boxstyle bet  while also removing any duplicates. (e.g. you want to target trifecta combinations containing one 'Frontrunner', one 'Stalker', & one 'Closer') [see Examples#3 & #4 below]
 When you want to target Trifecta combinations which require both a PRIMARY runner & a runner from a set of MAIN THREAT runners to finish among the top3 and then allow ANY runner to finish in the lone remaining position of the bet. [see Example#5 below]
In each of the above scenarios, the cost of the Power Box ticket can be substantially cheaper than playing a simple BOX bet containing the same number of runners.
Detailed Power Box ticket examples:
EXAMPLE #1
When you want to combine some runners in a boxstyle bet but you also want to reduce the ticket size/cost by "targeting specific combinations" of those runners ... e.g. target only those combinations that require a designated PRIMARY runner(s) of interest MUST finish on the winning ticket (top2 for Exacta, top3 for Trifecta, top4 for Superfecta).
A Trifecta Power Box player might target combinations of 3 sets of runners where:
(1) Your PRIMARY runner of interest (#1) must finish on the winning ticket (top3 for Trifecta) and
(2) One CONTENDER (from a set of selected 'Contenders'... #2,3,4) must also finish on the winning ticket and
(3) One LONGSHOT (from a set of other selected 'Longshots' ... #5,6,7) must also finish on the winning ticket.
e.g. A single Trifecta POWER BOX ticket of 1 with 2,3,4 with 5,6,7 covers all possible combinations between these 3 sets of runners "1", "2,3,4", "5,6,7" (54 combinations):
1 / 2,3,4 / 5,6,7 (9 combinations)
1 / 5,6,7 / 2,3,4 (9 combinations)
2,3,4 / 1 / 5,6,7 (9 combinations)
5,6,7 / 1 / 2,3,4 (9 combinations)
2,3,4 / 5,6,7 / 1 (9 combinations)
5,6,7 / 2,3,4 / 1 (9 combinations)
The above Power Box ticket conveniently targets 54 combinations (between the 7 selected runners). Whereas, a big 7horse BOX ticket would instead require covering 210 combinations.
EXAMPLE #2A
When you have TWO PRIMARY runners of interest (sometimes called a "DoubleKey") that you seek to combine with some other runners in a boxstyle bet... that is, you want to target combinations where both of your PRIMARY runners MUST finish somewhere on the winning ticket but you're not looking to key any runners in any specific position (e.g. only on top, or only underneath, etc). For example, a Superfecta player might target combinations where :
(1) BOTH PRIMARY runner #1 must finish among the top4
(2) and PRIMARY runner #2 must also finish among the top4
(3) and one CONTENDER (from a set of selected 'Contenders'... #3,4,or 5) must also finish among the top4
(4) and one LONGSHOT (from a set of other selected 'Longshots' ... #6,7,or 8) must also finish among the top4.
e.g. A single Superfecta Power Box ticket of 1 with 2 with 3,4,5 with 6,7,8 covers all possible Top4 combinations between the 4 sets of selected runners: "1", "2", "3,4,5", & "6,7,8" (216 combinations). Whereas, a goliath 8horse BOX ticket would instead require covering 1680 combinations.
EXAMPLE #2B
When targeting a nice paying Trifecta payoff, you may have TWO PRIMARY runners of interest (say, a WORTHY FAVORITE whom figures to finish no worse than third and a JUICY LONGSHOT of interest) that you would like to combine in Trifecta combinations with another set of selected CONTENDERS... that is, you want to target only those Trifecta combinations with your WORTHY FAVORITE, and your JUICY LONGSHOT, and (any) one of your other selected CONTENDERS to finish on the winning Trifecta ticket.
For example, you might want to target combinations where :
(1) A WORTHY FAVORITE runner #1 must finish among the top3
(2) and A JUICY LONGSHOT runner #2 must also finish among the top3
(3) and one CONTENDER (from a set of selected other 'Contenders'... #3,4,or 5) must also finish among the top3
e.g. A single Trifecta Power Box ticket of 1 with 2 with 3,4,5 covers all possible Top3 combinations between the 3 sets of selected runners: "1", "2", "3,4,5" (18 combinations):
1 / 2 / 3,4,5 (3 combinations)
2 / 1 / 3,4,5 (3 combinations)
1 / 3,4,5 / 2 (3 combinations)
2 / 3,4,5 / 1 (3 combinations)
3,4,5 / 1 / 2 (3 combinations)
3,4,5 / 2 / 1 (3 combinations)
The above Power Box ticket conveniently targets 18 specific combinations (between the 5 selected runners). Whereas, a 5horse BOX ticket would instead require covering 60 combinations.
EXAMPLE #2C
Similarly , when targeting a a nice paying Superfecta payoff, you may have TWO PRIMARY runners of interest (say, a WORTHY FAVORITE whom figures to finish no worse than fourth and a JUICY LONGSHOT of interest) whom you would like to combine in Superfecta combinations with other sets of your selected CONTENDERS... that is, you want to target only those Superfecta combinations with your WORTHY FAVORITE, your JUICY LONGSHOT, and your other selected CONTENDERS finishing on the winning Superfecta ticket.
For example, you might want to target combinations where :
(1) A WORTHY FAVORITE runner #1 must finish among the top4
(2) and A JUICY LONGSHOT runner #2 must also finish among the top4
(3) and two of your other selected runners (from your sets of selected CONTENDERS... #3,4,or 5) must fill the other remaining two Top4 positions.
e.g. A single Superfecta Power Box ticket of 1 with 2 with 3,4,5 with 3,4,5 covers all possible Top4 combinations between the 4 sets of selected runners: "1", "2", "3,4,5", & "3,4,5" (72 combinations). Whereas, a 5horse BOX ticket would instead require covering 120 combinations.
EXAMPLE #3
When you want to target all possible combinations containing exactly one runner from each of your selected runner sets/groups in a boxstyle bet
While groups of runners can be creatively defined in a large variety of ways, a Trifecta Power Box player might target runner group combinations where:
(1) One EARLY SPEED runner (from a set of selected 'Early Speed' runners... #1,2) must finish on the winning ticket (top3 for Trifecta) and
(2) One STALKER runner (from a set of selected 'Stalker' runners... #3,4) must also finish on the winning ticket and
(3) One CLOSER runner (from a set of selected 'Closer' runners... #5,6) must also finish on the winning ticket
e.g. A single Trifecta Power Box ticket of 1,2 with 3,4 with 5,6 covers all combinations among these 3 sets of runners "1,2", "3,4", "5,6" (48 combinations):
1,2 / 3,4 / 5,6 (8 combinations)
1,2 / 5,6 / 3,4 (8 combinations)
3,4 / 1,2 / 5,6 (8 combinations)
5,6 / 1,2 / 3,4 (8 combinations)
3,4 / 5,6 / 1,2 (8 combinations)
5,6 / 3,4 / 1,2 (8 combinations)
EXAMPLE #4
When you want to target all possible combinations between multiple sets/groups of your selected runners with a single ticket request (while also removing any duplicates). For example, you might want to target combinations where :
(1) PRIMARY runner #1 must finish among the top3
(2) and one MAIN THREAT runner (from a set of two selected MAIN THREATS... #2 & #3) must also finish among the top3
(3) and one CONTENDER (from a set of selected 'Contenders'... #2,3,4) must also finish among the top3.
e.g. A single Trifecta Power Box ticket of 1 with 2,3 with 2,3,4,5 covers all (30) combinations among these 3 sets of runners... "1", "2,3", "2,3,4,5" (30 combinations... with 6 duplicate combinations automatically removed):
1 with 2,3 with 2,3,4,5
1 with 2,3,4,5 with 2,3
2,3 with 1 with 2,3,4,5
2,3,4,5 with 1 with 2,3
2,3 with 2,3,4,5 with 1
2,3,4,5 with 2,3 with 1
EXAMPLE #5
When you want to target Trifecta combinations which require both a PRIMARY runner & a runner from a set of MAIN THREAT runners to finish among the top3 and then allow ANY runner to finish in the lone remaining position of the bet.
For example, you might want to target combinations where :
(1) PRIMARY runner #1 must finish among the top3
(2) and one MAIN THREAT runner (from a set of two selected MAIN THREATS... #2 & #3) must also finish among the top3
(3) and ALL (... #2  #10 for a tenhorse field) covers all other possible runners in the remaining top3 position.
e.g. A single Trifecta Power Box ticket of 1 with 2,3 with ALL covers all possible Top3 combinations between the 3 sets of selected runners: "1", "2,3", "ALL" (102 combinations in a tenhorse race).
A MoneySaving Tip when seeking to minimize ticket cost/size:
An effective way to reduce ticket cost/size is to restrict each selected runner to a single position/group/set ( e.g. "1" with "2,3,4" with "5,6,7"). That is, you can reduce ticket cost/size by avoiding use of any runners across multiple positions. And, since Power Box automatically swaps (or boxes) your selected runner positions across each position of the bet, every set of selected runner positions is still automatically covered in EACH position of the bet!
When reducing ticket cost/size by employing this type of ticketstructure, the player is effectively betting that exactly (and only) one selected horse from each set of selected runners will finish somewhere on the winning ticket (top2 for Exacta, top3 for Tri and top4 for Super, etc). Examples #1, #2A, #2B, and #3 (above) adhere to this moneysaving ticket building strategy:
1 with 2,3,4 with 5,6,7 [Example#1]
1 with 2 with 3.4,5 with 6,7,8 [Example #2A]
1 with 2 with 3,4,5 [Example #2B]
1,2 with 3,4 with 5,6 [Example #3]
Here is a video on Power Box Wagering: https://www.youtube.com/watch?v=7E2EV_ZdpJo