The Number Tracking Test (NTT) does two things: First, it represents a ***paper-and-pencil-based face-to-face contest paradigm that allows to experimentally manipulate winning and losing*** such that one participant of a dyad wins 8 out of 12 rounds and the other loses 8 out of 12 rounds. The difference it outcomes per round is achieved by different test length (hidden in the number matrix), with "losing" forms being considerable longer than "winning" forms. Stochastically, this usually works for any given pair of participants, except if their initial speed differences are too great. For that reason, I recommend pretesting and matching participants based on comparable task performance. The second purpose served by the NTT is that of a ***measure of implicit learning*** or, if the contest portion is included and the learning concerns a behavior that either overwhelmingly leads to success or failure, **implicit *instrumental* learning**. Learning is operationalized through a repetitive pattern of number connections on the *fixed* forms that is absent on the *random* forms. Learning can be assessed by the difference in performance on fixed and random forms administered before and after the contest portion. It also includes a layered awareness test probing for participants explicit knowledge of the pattern featured on the fixed forms. Please refer to the NTT document for further details and instructions. The NTT has been validated for both purposes by, and should be cited as: Schultheiss, O. C., & Rohde, W. (2002). Implicit power motivation predicts men's testosterone changes and implicit learning in a contest situation. Hormones and Behavior, 41, 195-202. It has been used to experimentally vary contest outcome only by a much larger number of studies, including these: Schultheiss, O. C., Campbell, K. L., & McClelland, D. C. (1999). Implicit power motivation moderates men's testosterone responses to imagined and real dominance success. Hormones and Behavior, 36, 234-241. Josephs, R. A., Sellers, J. G., Newman, M. L., & Mehta, P. H. (2006). The mismatch effect: when testosterone and status are at odds. Journal of Personality and Social Psychology, 90, 999-1013. Mehta, P. H., Jones, A. C., & Josephs, R. A. (2008). The social endocrinology of dominance: Basal testosterone predicts cortisol changes and behavior following victory and defeat. Journal of Personality and Social Psychology, 94, 1078-1093. Maner, J. K., Miller, S. L., Schmidt, N. B., & Eckel, L. A. (2008). Submitting to defeat: social anxiety, dominance threat, and decrements in testosterone. Psychological Science, 19, 764-768. Carré, J. M., Putnam, S. K., & McCormick, C. M. (2009). Testosterone responses to competition predict future aggressive behaviour at a cost to reward in men. Psychoneuroendocrinology, 34, 561-570. Mehta, P. H., & Josephs, R. A. (2010). Testosterone and cortisol jointly regulate dominance: Evidence for a dual-hormone hypothesis. Hormones and Behavior, 58, 898–906. Priem, J. S., & Solomon, D. H. (2011). Relational uncertainty and cortisol responses to hurtful and supportive messages from a dating partner. Personal Relationships, 18, 198-223. Oliveira, G. A., Uceda, S., Oliveira, T., Fernandes, A., Garcia-Marques, T., & Oliveira, R. F. (2013). Threat perception and familiarity moderate the androgen response to competition in women. Front Psychol, 4, 389. Vongas, J. G., & Al Hajj, R. (2017). The effects of competition and implicit power motive on men's testosterone, emotion recognition, and aggression. Hormones and Behavior, 92, 57-71.