In this extended abstract a large-scale analysis of 4- way Arbiter PUFs is performed with measurement results from 1000 RFID tags. Arbiter PUFs are one of the most important building blocks in PUF-based protocols and have been the subject of many papers. However, in the past often only software simulations or a limited number of test chips were available for analysis. Therefore, the goal of this work is to verify earlier findings in regard to the uniqueness and reliability of Arbiter PUFs by using a much larger measurement set. Furthermore, we used machine learning algorithms to approximate and compare the internal delay differences of the employed PUF. One of the main research questions in this paper is to examine if any “outliers” occurred, i.e., if some tags performed considerably different. This might for example happen due to some unusual manufacturing variations or faults. However, our findings are that for all of the analyzed tags the parameters fell within the range of a Gaussian distribution without significant outliers. Hence, our results are indeed in line with the results of prior work.