National oil companies (NOCs) appear resurgent in the global energy markets and now control a sizeable majority of the world's oil and gas reserves. Their performance therefore plays a key role in these markets and has implications for the supply of oil and gas resources. This paper analyzes available macro-level data on oil and gas companies in order to quantitatively compare the performance of NOCs with international oil companies (IOCs) including the global majors. Due to performance shortcomings or government-dictated strategies that differ from those of purely profit-maximizing enterprises, NOCs are seen to extract resources far less efficiently than IOCs. Much of the oil and gas reserves in NOC hands are thus effectively "dead." At the same time, NOC performance is far from monolithic - some national oil companies are able to perform at or near the level of the global majors, while others fall significantly short.