The WFTDA Strength Factor Challenge (SFC) Program provides a tool to give teams, who demonstrate that they merit a higher strength factor than they currently have, a temporary boost in strength factor to attract higher-ranked opponents for sanctioned play. Any league or event may apply for SFC games. The goal of the program is to encourage more sanctioned play, ultimately resulting in more accurate worldwide rankings.

Download: Strength Factor Challenge Program


What is a Strength Factor Challenge Game?

A Strength Factor Challenge game (SFC) is an unsanctioned game that a lower-ranked charter team (Challenging Team) schedules versus a higher-ranked charter team (Opponent Team) in order to attempt to temporarily increase their strength factor (SF). If they are successful with their challenge, the Challenging Team will be assigned a higher strength factor for a limited time (6 months), while there is no effect on the Opponent Team. A team can lose a SFC game and still be successful in their challenge.

The benefit to the Challenging Team is indirect. Having a higher strength factor that is more representative of their skill level will make a Challenging Team a more attractive opponent for subsequent sanctioned game play. Potential future opponents who would not have sanctioned games solely because the Challenging Team’s strength factor was too low, are more likely to schedule a game with the boosted strength factor.

Challenging Teams must choose their opponents for a SFC game wisely. A SFC game alone will not impact the Challenging Team’s rank — a team’s rank is purely based on successful sanctioned game results against more attractively ranked teams in the months in which the boosted strength factor is active.

How Does It Work?

  1. A Challenging Team schedules an SFC game versus an Opponent Team of a higher rank. See “How Do I Apply?” below for information on the application and approval process,
  2. After the game has been played, the scores from the game will be used to calculate the individual game points. (NOTE: The formula to calculate individual game points is located in the WFTDA Rankings Policy.)
  3. The individual game points will be used to calculate the strength factor using the median from the previous month. The calculated strength factor will be multiplied by a factor of 0.80 to determine the Challenging Team’s assigned strength factor.

    If the assigned strength factor is greater than or equal to 1.40 times the Challenging Team’s natural strength factor, then the assigned strength factor will be the boosted strength factor for the Challenging Team.

    If the assigned strength factor is less than 1.40 times the Challenging Team’s natural strength factor, then the Challenging Team’s natural strength factor will not be adjusted.

  4. The assigned strength factor will be effective for all sanctioned games played within a six-month period, starting with the month in which the SFC game was played. During the boost period, all teams playing the Challenging Team will have their game points calculated using the assigned strength factor, while the Challenging Team’s points will still be calculated using their opponent’s strength factor.

    The Challenging Team’s ranking will be calculated based on the average game points accumulated in the 12-month ranking period, so the boost will only appear in their strength factor.

  5. Teams can only make one strength factor challenge every 12 months. However, if they are not successful in an SFC game, they may appeal to WFTDA Rankings Committee to be permitted to issue a new challenge prior to the 12-month period expiring.

WFTDA Rankings Committee and WFTDA Competitive Play Committee reserve the right to change the parameters of the program in particular cases, should they feel it is necessary to achieve the competitive goals and mission of the WFTDA.

Can you give an example of an SFC and how it impacts rankings?

In March, Toaster City is ranked in the upper 100s, with a strength factor close to 1.0, and a WFTDA Ranking Points Average of 100 (which means the median WFTDA Ranking Points Average is also 100). They’ve had a few big wins over low-ranked teams, but are getting turned down by higher-ranked teams because of their low strength factor. They’ve scrimmaged higher-ranked teams and performed competitively.

Toaster City has two games in May scheduled, which could be sanctioned, so in April, Toaster City decides to challenge Water City, a team ranked around 100, with a strength factor of 1.75 in a Strength Factor Challenge game. The final score is Toaster City 120 – Water City 200. So what happens?

Toaster City’s assigned strength factor is treated as if this were their only sanctioned game. In this particular case, they’d achieve a calculated strength factor of 1.97. This is then multiplied by 0.8, yielding an assigned strength factor of 1.58. Since this is more than 1.40 times their natural strength factor of 1.0, it becomes their new boosted strength factor.

Summary of SFC game in April set up and outcomes (March’s Median is 100.00):

SFC Status
March Ranking
Natural SF
SFC Game Score
Calculated SF (CSF)
Assigned SF (CSF x 0.8)
Toaster City
Water City

(If, instead, the final score of the SFC game had been Toaster City 80 – Water City 200, Toaster City would have had a calculated Strength Factor of 1.5, which is then multiplied by 0.80 for an assigned Strength Factor of 1.2. However, as is less than 1.40 times their natural strength factor of 1.0, their strength factor would not be boosted, and they would retain their natural strength factor. They would be allowed to appeal to be permitted to play a second SFC within 12 months of the failed SFC.)

  1. Water City is not affected by the Toaster City challenge game in April – no adjustments or game scores are recorded in the Calculator for a team challenged in an SFC game.
  2. Toaster City is now more attractive to opponents for those two May games, so they are scheduled and sanctioned.
  3. All of Toaster City’s opponents’ sanctioned game points for April will be calculated using the 1.58 strength factor, which will increase the game points achieved in those games. Meanwhile, Toaster City’s natural strength factor and ranking will continue to be tracked based on their performance and the strength of their opponents in all sanctioned game play in the previous 12 months.

NOTE: The boosted strength factor for Toaster City will not be viewable on the Rankings Calculator until the month is completed. (In May, one can see Toaster City’s adjusted strength factor for April.)

  1. After April games are complete, Toaster City’s boosted strength factor remains higher than their natural strength factor, so Rankings manually enters the boosted strength factor of 1.58 for Toaster City.
  2. When May games are added, including Toaster City’s two sanctioned games, their opponents’ game points are based off the boosted 1.58 strength factor. Toaster City’s performance in those two sanctioned games will determine their new average, natural strength factor and ranking. If they were successful in these sanctioned games, their ranking and natural strength factor would increase accordingly.
  3. After May games are complete, Rankings will again compare Toaster City’s natural and boosted strength factor, and if the boosted strength factor remains higher, will manually enter the boosted strength factor of 1.58 for Toaster City at the end of the month.
  4. Toaster City will continue to have their strength factor boosted to 1.58 for use for sanctioned games scheduled in June, July, August, and September, and their opponents’ results will be calculated using that boosted strength factor. However if at the end of each ranking period, should their natural strength become greater than the boosted strength factor, the boosted strength factor will end.
  5. If their natural strength factor does not reach 1.58 at any ranking period, Toaster City’s boosted strength factor will expire once the September rankings are calculated, and only their natural strength factor will appear in the Calculator. All sanctioned game play starting in October will be based on their natural strength factor.

Strength Factor Challenge Game Requirements

  • Teams must apply for a Strength Factor Challenge when sanctioning is submitted, using the application process listed below.
  • The game must be played between two member league charter teams and must conform to all WFTDA sanctioning requirements.
  • New members must apply for a Strength Factor Challenge before playing sanctioned games. It is recommended that they select a team that has a natural strength factor of 1.00 or greater.  (Note: During the initial transition period, if a sanctioned game has been processed and WFTDA Rankings determines that it should have been a SFC game, the game will be processed as an SFC.)
  • At the time of the game, the Opponent Team must not be exercising a boosted strength factor.
  • If the Challenging Team succeeds in its challenge, they may only play one SFC game in a 12-month period.
  • If the Challenging Team fails in its challenge, they may appeal to play another SFC game within the same 12-month period.
  • If the Challenging Team is successful, the boosted strength factor will expire after six months, or should their natural strength factor move higher than the boosted strength factor, whichever comes first. This will be calculated at the end of each ranking period (month) when rankings are officially calculated.
  • If the Challenging Team makes a WFTDA Playoff or Continental Cup and the boosted strength factor is still in effect, the assigned strength factor will end and the team would use their natural strength factor. Assigned strength factors are not valid for Playoffs, Championships or Continental Cup tournaments.

How do I apply?

Applications for a Strength Factor Challenge game, as well as the charter rosters to be used for both teams, are due 30 days in advance of the game using the regular sanctioning process. WFTDA Rankings will review the sanctioning application as well as the charter rosters for each team in order to assess the viability of the Strength Factor Challenge game.

In their review, WFTDA Rankings will review both team charters against previously played games and will take into account issues like league turnover, particularly at the start of the year. WFTDA Rankings will grant the Opponent Team leeway for roster decisions due to the low-risk nature of the Strength Factor Challenge game. If Rankings deems that based on past performance of the Challenging Team, the stability of both charters, and/or the apparent distance between their natural strength factors that can result in a successful SFC, then the Strength Factor Challenge game will be accepted.

WFTDA Rankings may counsel for or against a Strength Factor Challenge game, but it is the responsibility of the Challenging Team to choose a game that best benefits their particular strength factor issue. WFTDA Rankings and WFTDA Competitive Play may also approve the use of SFC games in a tournament (outside of WFTDA Cups, Playoffs or Championships) or other event settings.

How do I submit my scores?

Scores, signed IGRFs and completed StatsBooks will be submitted to WFTDA as per WFTDA score reporting and games data requirements and deadlines. Please indicate that the game is a Strength Factor Challenge game when submitting these items.

WFTDA Rankings will approve and apply the appropriate boost per the process described above once the score is submitted and verified, starting with the ranking period in which the game was played.

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