spinner – Giga thoughts …

Here is a look at some of the masters of spin bowling in cricket. Specifically this post analyzes 3 giants of spin bowling in recent times, namely Shane Warne of Australia, Muthiah Muralitharan of Sri Lanka and our very own Anil Kumble of India. As to “who is the best leggie” has been a hot topic in cricket in recent years. As in my earlier post “Analyzing cricket’s batting legends: Through the mirage with R”, I was not interested in gross statistics like most wickets taken.

In this post I try to analyze how each bowler has performed over his entire test career. All bowlers have bowled around ~240 innings. All other things being equal, it does take a sense to look a little deeper into what their performance numbers reveal about them. As in my earlier posts the data has been taken from ESPN CricInfo’s Statguru

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Important note: Do check out the python avatar of cricketr, ‘cricpy’ in my post ‘Introducing cricpy:A python package to analyze performances of cricketers”

I have chosen these 3 spinners for the following reasons

Shane Warne : Clearly a deadly spinner who can turn the ball at absurd angles
Muthiah Muralitharan : While controversy dogged Muralitharan he was virtually unplayable on many cricketing venues
Anil Kumble: A master spinner whose chess like strategy usually outwitted the best of batsmen.

The King of Spin according to my analysis below is clearly Muthiah Muralitharan. This is clearly shown in the final charts where the performances of bowlers are plotted on a single graph. Muralitharan is clearly a much more lethal bowler and has a higher strike rate. In addition Muralitharan has the lowest mean economy rate amongst the 3 for wickets in the range 3 to 7. Feel free to add your own thoughts, comments and dissent.

The code for this implementation is available at GitHub at mastersOfSpin. Feel free to clone,fork or hack the code to your own needs. You should be able to use the code as-is on other bowlers with little or no modification

So here goes

Wickets frequency percentage vs Wickets plot
For this plot I determine how frequently the bowler takes ‘n’ wickets in his career and calculate the percentage over his entire career. In other words this is done as follows in R

# Create a table of Wickets vs the frequency of the wickts colnames(wktsDF) # Calculate wickets percentage wktsDF$freqPercent
and plot this as a graph.

This is shown for Warne below
1) Shane Warne – Wickets Frequency percentage vs Wickets plot

Wickets – Mean Economy rate chart
This chart plots the mean economy rate for ‘n’ wickets for the bowler. As an example to do this for 3 wickets for Shane Warne, a list is created of economy rates when Warne has taken 3 wickets in his entire career. The average of this list is then computed and stored against Warne’s 3 wickets. This is done for all wickets taken in Warne’s career. The R snippet for this implementation is shown below

econRate for (i in 0: max(as.numeric(as.character(bowler$Wkts)))) { # Create a vector of Economy rate for number of wickets 'i' a b # Compute the mean economy rate by using lapply on the list econRate[i+1] print(econRate[i]) }

Shane Warne – Wickets vs Mean Economy rate
This plot for Shane Warne is shown below

The plots for M Muralithan and Anil Kumble are included below

2) M Muralitharan – Wickets Frequency percentage vs Wickets plot

M Muralitharan – Wickets vs Mean Economy rate

3) Anil Kumble – Wickets Frequency percentage vs Wickets plot

Anil Kumble – Wickets vs Mean Economy rate

Finally the relative performance of the bowlers is generated by creating a single chart where the wicket frequencies and the mean economy rate vs wickets is plotted.

This is shown below

Relative wicket percentages

Relative mean economy rate

As can be seen in the above 2 charts M Muralidharan not only has a higher strike rate as far as wickets in 3 to 7 range, he also has a much lower mean economy rate

You can clone/fork the R code from GitHub at mastersOfSpin

Conclusion: The performance of Muthiah Muralitharan is clearly superior to both Shane Warne and Kumble. In my opinion the king of spin is M Muralitharan, followed by Shane Warne and finally Anil Kumble

Feel free to dispute my claims. Comments, suggestions are more than welcome

Also see

1. Informed choices through Machine Learning : Analyzing Kohli, Tendulkar and Dravid
2. Informed choices through Machine Learning-2: Pitting together Kumble, Kapil, Chandra
3. Analyzing cricket’s batting legends – Through the mirage with R

Unity – A simple unit converter is my first android app. The app in itself is no great piece of software wizardry but I managed to play around some of the basic android concepts. Currently in its current version there are just 4 main types of units – length, mass,temperature and volume each with just 2 unit types. I am planning to implement a full-fledged android version with all types of units and unit conversions shortly. Watch this space for more.

For this simple version I have a textfield to take user input of the value to be converted. I also have 2 spinners with the list of units. The first spinner (fromUnit) has its content loaded in runtime from an ArrayAdapter. The contents of the 2nd spinner is based on the selection of the 1^st spinner. So if the 1^st spinner chooses a length unit the 2^nd spinner will also be loaded with the length units and so on. There is also a Calculate button with a “convert” method for onClick to convert from the fromUnit to the toUnit.

The resource/activity_main.xml

<requestFocus />
</EditText>
<Spinner
android:id=“@+id/spinner1”
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:layout_alignParentLeft=“true”
android:layout_below=“@+id/editText1”
android:layout_marginTop=“24dp” />
<Spinner
android:id=“@+id/spinner2”
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:layout_alignParentLeft=“true”
android:layout_below=“@+id/spinner1”
android:layout_marginTop=“44dp” />
</RelativeLayout>
The fromUnit is based on the units array below
String[] units = {“kilogram”,“mile”,
“kilometer”,“pound”,“gallon”,“liter”,“centigrade”,“fahrenheit”,
};
In the onCreate() method I create an ArrayAdapter and set the spinner with this adapter as follows
final ArrayAdapter<String> adapter = new ArrayAdapter<String> (this,
android.R.layout.simple_spinner_item,units);
sp = (Spinner) findViewById(R.id.spinner1);
sp.setAdapter(adapter);
I also set the 2^nd spinner (toUnit) based on the selected unit in spinner 1. Hence I conditionally set the 2^nd spinner as follows
sp1 = (Spinner) findViewById(R.id.spinner2);
sp.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> argo0, View arg1,
int arg2, long arg3) {
int item = sp.getSelectedItemPosition();
fromUnit = units[item];
if( (fromUnit.equals(“kilometer”)) || (fromUnit.equals(“mile”))) {
sp1.setAdapter(lengthAdapter);
unitType=1;
}
else if ((fromUnit.equals(“kilogram”)) || (fromUnit.equals(“pound”))){
sp1.setAdapter(massAdapter);
unitType=2;
}
else if ((fromUnit.equals(“centigrade”)) || (fromUnit.equals(“fahrenheit”))) {
sp1.setAdapter(tempAdapter);
unitType=3;
}
else if((fromUnit.equals(“liter”)) ||(fromUnit.equals(“gallon”))){
sp1.setAdapter(volumeAdapter);
unitType=4;
}
else {
sp1.setAdapter(adapter);
unitType =5;
}
Toast.makeText(getBaseContext(),“You have selected: “ +
fromUnit, Toast.LENGTH_SHORT).show();
}
public void onNothingSelected(AdapterView<?> arg0) {
}
});
sp1.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> argo0, View arg1,
int arg2, long arg3) {
int item = sp1.getSelectedItemPosition();
if(unitType == 1) {
toUnit= lengthUnits[item];
}
else if(unitType == 2){
toUnit = massUnits[item];
}
else if(unitType == 3){
toUnit = tempUnits[item];
}
else if (unitType == 4) {
toUnit = volumeUnits[item];
}
else {
toUnit = units[item];
}
Toast.makeText(getBaseContext(),“SP2:You have
selected: “ +
toUnit, Toast.LENGTH_SHORT).show();
}
public void onNothingSelected(AdapterView<?> arg0) {
}
});
Finally based on the fromUnit and the toUnit the appropriate method is called in the onClick method of the Calculate button.
if((fromUnit.equals(“kilometer”)) && (toUnit.equals(“mile”))){
text.setText(String.valueOf(convertkilometer2mile(inputValue)));
}

else if((fromUnit.equals(“mile”)) && (toUnit.equals(“kilometer”))) {
text.setText(String.valueOf(convertmile2kilometer(inputValue)));
}
and so on…
While this is an elementary app I intend to develop a more thorough version shortly with some of the good features of android.
The complete code can be downloaded from the link Unity.zip