Uber director Lindsay Maxsted, once thought to have been past the prime of his career, has resurrected himself as Australia’s most powerful director as measured by the size of the company boards on which he sits.

Exclusive research undertaken for The Power Index by leading ASX number crunchers Optimice reveals Maxsted’s three board spots at global miner BHP Billiton, toll roads operator Transurban and Westpac (as chairman) total a hulking $191 billion, nearly $77 billion clear of second place-getter and fellow BHP director Carolyn Hewson.

If capital is power then Maxsted is the reigning boardroom king, piggybacking off the mining boom and calling the shots inside one of Australia’s famously uncompetitive banking pillars sometimes accused of gouging fees from ordinary citizens to featherbed multi-billion dollar profits.

Crucially for the stubbly KPMG lifer — he entered the accounting firm as a 19-year-old cadet and left as CEO after 34 years in 2008 — Maxsted is the only member of the 72-strong Market Capitalisation Influence Index (MCII) to boast both a Big Four directorship and BHP. Combine the two and you’re a sure thing on the MCII list, which is based on official Thomson Reuters data drawn from the ASX on October 26 this year. To make it on, your boards need a combined market cap of over $50 billion.

The next three MCII positions are all held by BHP directors: Scotch College old boy David Crawford ($111 billion), former Orica boss Malcolm Broomhead ($110 billion) and ex-Commonwealth Bank chair John Schubert ($108 billion).

Just a few months ago things might have been different. Hewson, in a fatal move, left the Westpac board in June, having reached the bank’s maximum nine-year limit for serving directors — but even if she’d been able to somehow convince the company to stay on she still wouldn’t have been able to pip Maxsted for the top slot. Interestingly, Hewson served as a kind of canary down the coal mine, preceding her friend’s entry onto both BHP and Westpac, and the two remain close. She also serves on BT Investment Management and Stockland.

Indeed, the presence of the diversified iron ore behemoth is almost a prerequisite for a spot on the MCII — eight of the top 10 boast BHP in their portfolio. And it could have been an even bigger whitewash — the Optimice data only includes the the market cap of the miner’s local shares (today’s total global market cap is approaching $175 billion). BHP’s major competitor, the similarly dual-listed Rio Tinto, would also warp things given the inclusion of its global market cap of $93 billion would inject every one its directors — names like Mike Fitzpatrick and former BHP CFO Chris Lynch — onto the MCII. But, like BHP, only its ASX shares were included.

Mining companies are one of three main threads running through the prestigious list, dominated by Telstra (market cap: $49 billion) and the Big Four. Among the banks, CBA is out in front with market cap of $89 billion, followed by Westpac on $77 billion, ANZ on $67 billion and NAB on $59 billion.

Click through to the full list of ASX directors

The MCII rankings are a subset of The Power Index’s top 10 directors list, which is counting down the most powerful and influential directors based on a broader range of factors including boardroom connectedness, third-party interviews, number of chairperson roles and not-for-profit “trophy boards”.

Interestingly, a number of leading contenders for The Power Index top 10 — including David Gonski, Roger Corbett, Bob Every and Robert Millner — are nowhere to be found in the MCII’s upper echelons.

Women are also under-represented, holding just 16 of the 72 slots, or 22%. Even so, that figure is higher than the total percentage of women on the ASX 200 — 15.2% — suggesting leading women are more likely to flex their muscle at the top of the index. Leading MCII women include the multi-faceted veteran Hewson, Jane Hemstritch (CBA, Lend Lease, Santos, Tabcorp), Carolyn Kay (Brambles, CBA) and Paula Dwyer (ANZ, Leighton, Tabcorp). Professional director and privatisation specialist Nora Scheinkestel (AMP, Orica, Pacific Brands, Telstra) is also a powerful player.

The Tabcorp board, with a relatively small market cap of $2 billion, remains an intersection for the fiercely competitive Big Four thanks to the interlocking directorships of Hemstritch and Dwyer. It has historically acted as a halfway house for directors who would naturally refrain from ever mentioning current deliberations at their other, higher-profile, gigs.