Is the Southee - Boult partnership greater than the Hadlee - Chatfield partnership?

There is a theory that bowlers are supposed to hunt in a pack. That the two bowlers are supposed to work together to get the batsmen out.  There are some proponents of this theory, and some who feel that it is rubbish, and that each bowler is wholly responsible for their own figures.

In the light of their recent performances I've been looking into the opening partnership of Boult and Southee and then I've compared that to others opening partnerships throughout time. They are a fairly new pair, but they actually stack up quite well.

Their Test Partnership

In the 14 test matches that they have played in together they have taken 114 wickets at 24.83. They have taken a wicket roughly every 9 overs and have gone at less than 3 an over. These are impressive numbers.  But it does beg the question as to what they do when they are not playing together.

In the 19 matches where only one of them has been playing they have taken 47 wickets at 43.79. In those matches they take a wicket roughly every 13 overs and concede about 3.4 per over.

When Boult and Southee are both playing, Boult averages 23.66 and Southee averages 26.00. When they are not together Boult averages 45.50 and Southee averages 43.32.

Tim Southee's release point

There are a couple of possible reasons for this. Perhaps it is because they are friends, and have played together since they were teenagers. The presence of their friend on the field means that they perform better.

Or perhaps it is because they ask different questions of the batsmen. Southee attacks a right-handed batsman's body, then moves the ball away while Boult starts the ball going across him, then brings it back in. Boult has a different release point than Southee, so while they both often bowl the same speed; the pace that the batsman perceives the ball is different, depending on the length they are bowling.

It could also be that they are both swing bowlers and so they don't have a seam bowler sending down cutters that damage the ball from the other end.

But regardless it is clear that they seem to have more success when they are bowling together than apart in tests. That made me wonder if it was true for Northern Districts, the regional side they both play for.

First Class Partnership

For Northern Districts the same pattern repeats itself. Here is a table of their averages:

	Boult	Southee	Combined
Together	12.82	14.41	13.62
Apart	28.74	18.31	24.63

It's clear again that they have an impact on each other. They have much better numbers when they are playing together.

Historical Context

I wondered if this massive difference was true for other bowling partnerships. This turned out to be quite difficult to find out. First of all I decided to try and find the averages for the most famous bowling partnerships of all time. I'm reasonably knowledgeable about the history of test cricket, but I certainly knew that I wouldn't be able to name every successful opening partnership. I made a list of the 10 that I thought would be the best, then I used some crowd sourcing. I also looked at every opening bowler who had played more than 50 matches and averaged less than 30. I also only looked closely at post-war matches, as the nature of opening bowling has changed quite a lot since then.

I only counted opening partnerships that had played 10 matches together.

I ended up with a list of 33 partnerships. There are probably some that I have missed, so feel free to let me know in the comments below about any great partnerships that you would like included.

The first thing that I did was find out the average for each partnership, and then rank them. Here's the top 20:

Partnership	Average
Steyn - Philander	19.51
Davidson - Meckiff	21.40
Marshall - Garner	21.72
Donald - Pollock	21.85
Adcock - Heine	22.08
Waqar Younis - Wasim Akram	22.12
Philander - Morkel	22.35
Walsh - Ambrose	22.68
Holding - Marshall	22.77
Lindwall - Miller	23.00
McGrath - Gillespie	23.02
Alderman - Hughes	24.13
Imran Khan - Wasim Akram	24.30
Southee - Boult	24.83
Bond - Martin	25.01
Botham - Willis	25.18
Steyn - Morkel	25.25
McGrath - Lee	25.32
Hadlee - Chatfield	25.39
Holding - Roberts	25.66

The first thing that I noticed was just how good Vernon Philander's numbers are. He has two entries in the top 7. I also noticed that most of the partnerships were two different types of bowlers. They were either a combination of swing and seam, tall and short, fast and medium or right arm and left arm.

Southee and Boult actually came in top of New Zealand's list, ahead of Bond and Martin and Hadlee and Chatfield.

Comparing the Difference

I then looked at each partnership and how the bowlers went together as opposed to when they were apart. Here I had to cut out a few partnerships. I only counted them if both players had played at least 5 matches without their partner. Curtly Ambrose only played 3 matches without Courtney Walsh, and Vernon Philander has never played a test without Dale Steyn, so I couldn't do a fair comparison for either of these.

This table was a very surprising result.

Partnership	Together	Apart	Difference
Southee - Boult	24.83	43.79	43.3%
Bond - Martin	25.01	32.53	23.1%
Alderman - Hughes	24.13	30.23	20.2%
Waqar Younis - Wasim Akram	22.12	27.19	18.6%
Botham - Willis	25.18	30.52	17.5%
Anderson - Broad	29.50	34.29	14.0%
Vaas - Malinga	28.14	31.32	10.2%
Donald - Pollock	21.85	23.74	8.0%
Harmison - Hoggard	30.61	32.45	5.7%
Cairns - Doull	28.67	29.86	4.0%
McGrath - Gillespie	23.02	23.12	0.4%

Southee and Boult seem to have the biggest impact on each other of any bowlers in history.

Comparison with Hadlee - Chatfield

Most New Zealand fans who have any sense of history would suggest Hadlee and Chatfield as New Zealand's greatest bowling partnership. So it is interesting to see how the Southee/Boult combination compares to them.  First of all I looked at the wickets per match throughout their career.

We see that Boult and Southee are tracking along a similar path to what Hadlee and Chatfield were at a similar stage in their partnership.

It is useful to zoom in a little to see it more clearly:

We can see that the two lines are tracking extremely closely. They are almost totally indistinguishable from each other.

Both partnerships take roughly 8 wickets per test. The Hadlee - Chatfield partnership tended to have Hadlee taking a larger proportion of the wickets than Chatfield, but the totals are very similar.

The next thing that I looked at was the averages of each partnership. I looked at the big picture and then also I zoomed in to see any differences.

This was quite interesting because again there was some similarities between the two lines.

The Southee - Boult line is slightly lower, as they have conceded less runs, despite taking roughly the same number of wickets.

The final graphs are a look at the individual contributions. There is no doubt that Sir Richard Hadlee was a great bowler, but these two (at least while bowling together) are actually both tracking similarly to his career progression at the same point.

It is still early days for Boult and Southee, but the signs are certainly encouraging. If they continue to bowl as well together as they have, then they will be a real threat to any team's top order.