根据美军的书，战区分配是到达易北河才定的也是老艾拒绝牺牲十万人而进柏林之后-1945年4月21日定的：

https://history.army.mil/books/70-7_22.htm

On 21 April the Supreme Commander notified the Russians that, since the logistical position of the Allies was stretched in the center as a result of the rapid drive to the Elbe, they would make no move at that point for some weeks at least. He added that he expected to cross the Elbe in the north to open the north German ports and to drive the Germans north of the Kiel Canal. Other forces were to go southward into the Danube valley. On the following day he suggested that, since a meeting appeared likely in the Wittenberg-Dresden area, he would choose the line of the Elbe-Mulde on the central front as an easily identified line. [26] If the Russians wanted to stop on the Elbe and desired the Western Allies to advance eastward to Dresden, he was willing to do so. He suggested a firm junction on a recognizable line before final mutual adjustments based on local tactical situations were made. [27]

The Russians accepted the line of the Elbe and the Mulde on 24 April. General Alexei Antonov, Red Army Chief of Staff, added that the Soviet Command contemplated occupying Berlin and clearing the Germans from the east bank of the Elbe north and south of Berlin and from the Moldau River valley. [28] This last provision meant that Prague would be taken by the Russians.

4月21日，最高指挥官通知俄罗斯人，由于盟军的后勤位置由于快速驶向易北河而在中心被拉伸，他们至少在几个星期内不会采取任何行动。他补充说，他预计将穿越北部的易北河，打开德国北部的港口，并将德国人开往基尔运河以北。其他部队则向南进入多瑙河流域。第二天，他提出，由于可能会在维滕贝格 - 德累斯顿地区举行会议，他会选择中央前方的易北河 - 穆尔德线作为易于识别的线路。 [26]如果俄罗斯人想要停留在易北河上，并希望西方同盟国向东推进到德累斯顿，他愿意这样做。在根据当地战术情况进行最终相互调整之前，他建议在可识别的线路上建立牢固的交叉点。 [27]

俄罗斯人于4月24日接受了易北河和穆尔德的线路。红军参谋长阿列克谢·安东诺夫将军补充说，苏联司令部考虑占领柏林，并从柏林北部和南部的易北河以及Moldau河谷清除德国人。 [28]这最后一条规定意味着布拉格将由俄罗斯人占领。

 

 

所以这个比赛本就不成文：

Berlin was listed as the military goal of the Western Powers by SHAEF in a pre-D-Day plan of May 1944. 

在1944年5月的D日计划中，柏林被SHAEF列为西方军事的军事目标。

1945年4月7日时，老艾就说过苏军已经在柏林的35英里，然后加上美英军可能有十万伤亡直接进入被炸成废墟已经没有多少军事价值的柏林就觉得算了所以4月21日定了和苏联战区分配的计划。这些就是因为苏军的进军速度而造成的局势使老艾不得不重新考虑美英在西面的军事目标从而结束这场不成文的柏林赛跑。

 

所以你所说就是不承认有过这场不成文的赛跑所以本末颠倒说“你得证明盟军越过了美苏战区分界线，并向柏林有大幅度地推进才行”却不知这个“战区分界线”是因为老艾觉得已经没有意思才顶住各方压力正式退出这个比赛才定下的。