On Debate.org debates, there is, on balance, a net Contender advantage.

Thank you, Ore_Ele, for your response. I. General Trends My opponent proposes an alternate hypothesis to the Contender advantage, claiming that instead the Instigator is on average less skilled than the Contender. To prove this, he uses ELO scores themselves based on the results of the debate. This reasoning is somewhat circular, as it uses the results of the debates to decide the skill of the debaters, leaving nowhere to eliminate any theoretical Contender advantage. Should a Contender advantage exist, the supposed difference of skill in the debaters would actually be caused by this advantage; frequent Contenders would win debates more often, thus appearing more skilled under my opponent's system. Essentially, this leaves us nowhere; if a Contender advantage exists, then it will explain the ELO disparity, and if it doesn't, then it won't. Therefore, all of my opponent's conclusions drawn from ELO statistics are biased and useless, presupposing that the resolution is false to prove that the resolution is false. Look at my opponent's statistics regarding the 3k group. If a Contender advantage exists, then the frequent Instigators in this group are actually more skilled than they appear, and frequent Contenders are actually less skilled. Therefore, an evenly split win ratio is to be expected. This assumes, of course, that the ELO rank is perfectly reliable, and that nobody reverses their side; if people are shifting around, then there could also be an additional Contender advantage despite all attempts to quell it - and there is. My opponent is correct in that many debates have Instigator forfeits; however, many debates have Contender forfeits, as well. In fact, many of the debates that my opponent uses in an attempt to refute the Contender advantage, in his 3k group, are Contender forfeits (6590, 3546, 10565), partly-forfeits (4095, 7875, 14417), naivety (3563, 5825, 16751), or the result of vote-bombing and only vote-bombing (8375, 8543). Meanwhile, only one Instigator victory (8340) should be discarded. Since most Instigator victories don't qualify for this debate, we are instead left with 5 victories out of 20 debates, a dismal 0.25 win ratio that a one-proportion z-test says could only occur with 0.0127 probability due to random chance alone. With our established 95% threshold, we must reject the null hypothesis and accept that there is a Contender advantage. I would apply this same reasoning to his 4k group, but he does not link to the debates, and there are way too many debates for me to want to properly analyze all of them. I believe that the evidence on the 3k group should suffice to expose the true trend. My opponent's additional analyses of his statistics are irrelevant, as I've shown that they are based on faulty assumptions and poorly handled data. My opponent also doesn't seem to properly understand how proportion statistics work. When analyzing his 3k and 4k group data, he chose to use a z-test instead of a one-proportion z-test, making up a standard deviation of 1, which is a clear indicator that he is using the wrong test; we are dealing with successes and failures, which means we must use proportion statistics. If one replaces the standard deviation with another value, like 0.1, then the null hypothesis is rejected at the 5% significance level that we've chosen. If we apply a one-proportion z-test to his data instead, as we should, we get instead a p-value of 0.130. If we further assume that we really should expect the Instigator to win as often as the Contender because of the Contender bias present in the ELO system, we get a p-value of 0.042, which passes the necessary threshold; we therefore hold that there is a Contender advantage. To conclude my point, my opponent's data collection, assumptions, and statistical tests are all faulty, and when we correct for these failures, we find evidence not for neutrality but for a Contender advantage, turning this entire point. II. Specific Examples It is naturally unsurprising that the Contenders have high ELO scores if one assumes that there is a Contender advantage and the Contender wins artificially more often than the Instigator; it goes back to the circular reasoning behind using ELO scores that I identified before. The one Instigator victory in the group was a close one, by 2 points, as an artificial advantage does not guarantee victory; it need only appear and be identified for proof of its existence. My opponent makes no attempt to refute the apparent Contender advantage gained from having the last word, claiming that it would take too many characters. I identified five claims made, then explained why they are examples of the Contender advantage with fewer than 3,000 characters, repeating myself considerably often; he should require no more than that for refutations. Instead, he supposes some vague Instigator advantages, but these do not appear to be advantages at all. The Instigator may set the resolution and definitions, but the Contender may negotiate both before accepting the debate, sometimes even rejecting the definitions after they have been chosen by the Instigator, appearing to be instead a disadvantage instead of an advantage for the Instigator (10398). My opponent also claims that the Instigator can essentially trick the Contender with definitions that are biased towards the Instigator without appearing to be biased towards the Instigator, or the Contender can simply misunderstand. I can only recall two debates in which this appeared to occur in any form (8426, 8527). In the first, the voters rather overwhelmingly decided that the trickery was poor conduct and voted for the Contender instead. In the second, the Contender misunderstood the definitions by his own naivety. Sometimes, the Instigator can even shoot himself in the foot with definitions that make his own case much more difficult (8088, 10752), but this should be attributed not to any inherent advantages or disadvantages but instead to the naivety of the Instigator. Likewise, a Contender who accepts a debate in which the definitions are stacked against him without using his power to negotiate is equally naive. Additionally, the Instigator is traditionally charged with the burden of proof. This wouldn't be much of a problem if it weren't for the fact that the Instigator also runs into problems transferring the burden even in the first round, before acceptance (8601), giving the Contender even more advantage. My opponent accuses me of cherry-picking my examples, but there is no more effective way to demonstrate the Contender advantage than to identify examples of it in action. It could legitimately be cherry-picking if I consciously ignored any examples of Instigator advantage to show that only a Contender advantage exists, but I don't believe that such an advantage exists, and my opponent likewise hasn't come up with any concrete examples, either. If my opponent believes that there are any debates that demonstrate an Instigator advantage that I have skipped over, then I suggest he post them. As it stands, we only have examples of Contender advantage, so if we assume that sometimes a debate has a Contender advantage and other times there is no advantage, then when everything is taken as a whole, there is overall a slight Contender advantage. It's simple math; the average of a thousand zeros and a few negative numbers will come out negative. In conclusion, not only do the statistics clearly indicate that a Contender advantage exists despite my opponent's best efforts, but we also have solid examples of the Contender advantage in action. Good luck, Ore_Ele. [Sources: All debates sourced are referred to by their debate number. All z-test statistics came from Wolfram Alpha. All one-proportion z-test statistics were one-sided and came from a TI-84 graphing calculator, using the data referenced and a p0 value of 0.5 unless otherwise specified.]