This method retains the 50% chance of yin:yang, but changes the ratio of moving "yang" to static "yang" from 1:3 to 1:7; likewise, it changes the ratio of moving "yin" to static "yin" from 1:3 to 3:5, which is the same probabilities as the yarrow-stalk method. Some purists contend that there is a problem with the three-coin method because its probabilities differ from the more ancient, yarrow-stalk, method. In fact, over the centuries there have even been other methods used for consulting the oracle. The two-coin method involves tossing one pair of coins "twice": on the first toss, two heads give a value of 2, and anything else is 3; on the second toss, each coin is valued separately, to give a sum from 6 to 9, as above. This results in the same distribution of probabilities as for the yarrow-stalk method. With tails assigned the value 0 (zero) and heads the value 1, four coins tossed at once can be used to generate a four-bit binary number, the right-most coin indicating the first bit, the next coin (to the first's left) indicating the next bit, etc. The number 0000 is called "old yin"; the next three numbers—0001, 0010, and 0011 (the binary numbers whose decimal equivalents are 1, 2, and 3, respectively)—are called "old yang", with a similar principle applied to the remaining twelve outcomes. This gives identical results to the yarrow-stalk method. The two-coin method described above can be performed with four coins, simply by having one pair of coins be alike—of the same size or denomination—while the other two are of a different size or denomination; the larger coins can then be counted as the first toss, while the two smaller coins constitute the second toss (or "vice versa"). Six coins—five identical coins and one different—can be thrown at once. The coin that lands closest to a line drawn on the table will make the first line of the hexagram, and so on: heads for yang, tails for yin. The distinct coin is a moving line. This method has the dual failings that (1) it forces every hexagram to be a changing hexagram, and (2) it only ever allows exactly one line to be changing. Eight coins, one marked, are tossed at once. They are picked up in order and placed onto a Bagua diagram; the marked coin rests on the lower trigram.