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Explainer: how Smart Stats works

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ESPNcricinfo's Superstats - an explainer (1:32)

A quick look at how our new T20 metrics works (1:32)

Cricket is a unique sport in that it has three formats, which are so distinct from one another. Test cricket is a marathon that places a premium on longevity, discipline and endurance, Twenty20 is a sprint where explosive power is key, while the 50-over game is somewhere in between.

But the metrics used to measure performances have remained the same: averages, strike rates, economy rates. While they are all useful measures, they often don't tell the whole story because they lack context.

Superstats is a new language for numbers-based story-telling in cricket. The bouquet consists of three elements: Smart Stats, which puts each batting and bowling performance into context by looking at match situations and player quality; Luck Index, which - for the first time - quantifies the element of chance in cricket; and Forecaster, which does a spot of crystal-ball-gazing and predicts win probabilities in each game.

These metrics have been derived from ESPNcricinfo's rich ball-by-ball database, and from complex algorithms developed by IIT Madras and Gyan Data, an IIT-M incubated company.

Together, these three metrics will lead to far richer and more insightful stats-based stories for the cricket fan. It will also give the fans the opportunity to engage with the game in newer ways, making it more fun and entertaining to follow, while at the same time getting them more deeply involved with the nuances of the game.

To start with, here are the basic FAQs on Smart Stats: the factors considered, and the outputs. Click here to get your answers to similar questions about Luck Index and Forecaster. To check the Luck Index and Forecaster results when applied to IPL 2018, click here, and here get the Smart Stats results from IPL 2018.

What is Smart Stats?
Smart stats is a new way of looking at numbers, by adding context to every performance, batting and bowling. Context includes pitch conditions, quality of opposition, and match situation - in terms of the pressure on the player.

Smart Stats thus measures the true value of every batting/bowling performance.

Why do we need Smart Stats?
Any keen follower of cricket knows that all runs scored and wickets taken are not the same. A run scored under pressure, with the match in the balance, against a top opposition means much more than a run scored in a simpler situation. Similarly, getting someone like Virat Kohli out cheaply means a lot more than getting a tailender's wicket. Smart Stats makes these distinctions, and puts context to these numbers.

Let's look at Dinesh Karthik's eight-ball 29 in the Nidahas Cup final last year. It was truly exceptional because of the circumstances in which he scored those runs: India needed 34 off 12 to beat Bangladesh, after the previous six balls had yielded only one run. The value of the same innings would have been completely different had it come in a lost cause, or if it had come when the team was cruising. The same applies to bowling as well - the worth of a wicket could be completely different depending on the batter and the state of the game.

By bringing in context, Smart Stats tells you what each performance is truly worth.

How is Smart Stats calculated?
For every ball bowled, Smart Stats gives a value to every run scored or conceded, and every wicket taken, depending on:
- The batter at the crease and the bowler bowling
- The match context, in terms of the required run rate/wickets in hand for the batting team
- The quality of batsmen to follow
- The quality of bowlers who will bowl the remaining overs

Based on the above factors, a pressure-index value is assigned each ball, for the batter and the bowler. Each run scored or conceded is multiplied by this pressure-index value to give us the smart runs scored or conceded off that ball.

What are the new set of metrics?
- Smart runs
- Smart wickets
- Smart strike rate
- Smart economy rate
- Player impact (at a match level and over a period of time)

Can you explain each?
Smart Runs: The runs scored, taking context into account. So, a 30-ball 45 might be worth 50 or 40, depending on when the innings was played and the relative worth of the runs.

Smart wickets: The true value of wickets taken. This is calculated taking into account the quality of the batter, when the batter was dismissed - early in his innings or late - and the match context at the time - was the match in the balance, or was the result already a foregone conclusion.

Smart strike rate: Smart runs divided by balls faced

Smart economy rate: Smart runs conceded by overs bowled

Player Impact: The actual contribution of a player, combining both batting and bowling stats, to his team's cause in a match. The bowler's wickets are converted into a run value, so that all numbers are on the same scale. Thus, the player who tops this value is the MVP of the match based on the factors considered above. A player who performs poorly in the match gets a negative value.

So does that mean the actual leaders in Smart runs and Smart wickets in IPL 2018 could be different from the Orange Cap and Purple Cap holders?
Yes, it does. According to Smart numbers, Rishabh Pant should have been the Orange Cap holder of IPL 2018, while the Purple Cap should have gone to Rashid Khan. The actual awards went to Kane Williamson and Andrew Tye. Both Williamson and Tye are second in terms of smart numbers.

Can we select the Player of the Match from Smart Stats?
Yes, we can. The Player Impact numbers from each game tells us the top player based on their batting and bowling performances, which can be used to nominate the Player of the Match. However, there is a limitation here, since Smart Stats does not take into account fielding performances.